Grammar checker
Encyclopedia
A grammar checker in computing
terms, is a program
, or part of a program, that attempts to verify written text for grammatical correctness. Grammar checkers are most often implemented as a feature of a larger program, such as a word processor
, but are also available as stand-alone application
that can be activated from within programs that work with editable text.
The implementation of a grammar checker makes use of natural language processing
.
systems as far back as the 1970s. The whole Writer’s Workbench package included several separate tools to check for various writing problems. The ‘diction’ tool checked for wordy, trite, clichéd or misused phrases in a text. The tool would output a list of suspect phrases, and provide suggestions for improving the writing. The ‘style’ tool analyzed the writing style of a given text. It performed a number of readability tests on the text and output their results, and it gave some statistical information about the sentences of the text.
Aspen Software of Albuquerque, NM, released the earliest version of a diction and style checker for personal computers, Grammatik
, in 1981. Grammatik was first available for a Radio Shack
- TRS-80
, and soon had versions for CP/M
and the IBM PC
. Reference Software of San Francisco, CA, acquired Grammatik in 1985. Development of Grammatik continued, and it became an actual grammar checker that could detect writing errors beyond simple style checking.
Other early diction and style checking programs included Punctuation & Style, Correct Grammar, and RightWriter. While all the earliest programs started out as simple diction and style checkers, all eventually added various levels of language processing, and developed some level of true grammar checking capability.
Until 1992, grammar checkers were sold as add-on programs. There were still a large number of different word processing programs available at that time, with WordPerfect
and Microsoft Word
the top two in market share. In 1992, Microsoft
decided to add grammar checking as a feature of Word and licensed CorrecText, a grammar checker from Houghton Mifflin
that had not yet been marketed as a standalone product. WordPerfect answered Microsoft’s move by acquiring Reference Software, and the direct descendant of Grammatik is still included with WordPerfect.
d, or misused phrases in a text. This process was based on simple pattern matching
. The heart of the program was a list of many hundreds or thousands of phrases that are considered poor writing by many experts. The list of suspect phrases included alternative wording for each phrase. The checking program would simply break text into sentences, check for any matches in the phrase dictionary, and flag suspect phrases and show an alternative. These programs could also perform some mechanical checks. For example, they would typically flag doubled words, doubled punctuation, some capitalization
errors, and other simple mechanical mistakes.
True grammar checking is more complex. While a computer programming language has a very specific syntax and grammar, this is not so for natural language
s. Though it is possible to write a somewhat complete formal grammar
for a natural language, there are usually so many exceptions in real usage that a formal grammar is of minimal help in writing a grammar checker.
One of the most important parts of a natural language grammar checker is a dictionary
of all words in the language, along with the part of speech of each word. The fact that natural words can take many different parts of speech greatly increases the complexity of any grammar checker.
A grammar checker will find each sentence in a text, look up each word in the dictionary, and then attempt to parse the sentence into a form that matches a grammar. Using various rules, the program can then detect various errors, such as agreement in tense
, number, word order
, and so on.
It is also possible to detect some stylistic problems with the text. For example, use of the passive voice
is criticized by popular style guides such as The Elements of Style
. Grammar checkers may attempt to identify passive sentences and suggest an active-voice alternative.
The software elements required for grammar checking are closely related to some of the development issues that need to be addressed for voice recognition software. In voice recognition, parsing can be used to help predict which word is most likely correct based on part of speech and position in the sentence. In grammar checking, the parsing is used to detect words that fail to follow proper grammar usage.
Recently, research has focused on developing algorithms which are capable of recognizing grammar
errors based on the context of the surrounding words. Context-based grammar
checkers appear in Microsoft Office 2007
, Google Wave
, NeuroGrammar, Grammarly, Ginger Software, and in Ghotit Dyslexia context spell and grammar checker tuned for people with dyslexia.
s, popular grammar checkers are often criticized when they fail to spot errors and incorrectly flag correct text as erroneous. The linguist Geoffrey K. Pullum has argued that they are generally so inaccurate as to do more harm than good: "for the most part, accepting the advice of a computer grammar checker on your prose will make it much worse, sometimes hilariously incoherent."
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
terms, is a program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...
, or part of a program, that attempts to verify written text for grammatical correctness. Grammar checkers are most often implemented as a feature of a larger program, such as a word processor
Word processor
A word processor is a computer application used for the production of any sort of printable material....
, but are also available as stand-alone application
Application software
Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
that can be activated from within programs that work with editable text.
The implementation of a grammar checker makes use of natural language processing
Natural language processing
Natural language processing is a field of computer science and linguistics concerned with the interactions between computers and human languages; it began as a branch of artificial intelligence....
.
History
The earliest “grammar checkers” were basically programs that checked for punctuation and style inconsistencies, rather than finding many actual grammatical errors. The first system was called Writer's Workbench, and was a set of writing tools included with UnixUnix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
systems as far back as the 1970s. The whole Writer’s Workbench package included several separate tools to check for various writing problems. The ‘diction’ tool checked for wordy, trite, clichéd or misused phrases in a text. The tool would output a list of suspect phrases, and provide suggestions for improving the writing. The ‘style’ tool analyzed the writing style of a given text. It performed a number of readability tests on the text and output their results, and it gave some statistical information about the sentences of the text.
Aspen Software of Albuquerque, NM, released the earliest version of a diction and style checker for personal computers, Grammatik
Grammatik
Grammatik was the first grammar checking program developed for home computer systems. The first version was released in 1980 for the TRS-80 with subsequent versions being released for the DOS, Windows, Macintosh and Unix platforms. Grammatik was ultimately acquired by Corel and is integrated in the...
, in 1981. Grammatik was first available for a Radio Shack
Radio shack
Radio shack is a slang term for a room or structure for housing radio equipment.-History:In the early days of radio, equipment was experimental and home-built. The first radio transmitters used a noisy spark to generate radio waves and were often housed in a garage or shed. When radio was first...
- TRS-80
TRS-80
TRS-80 was Tandy Corporation's desktop microcomputer model line, sold through Tandy's Radio Shack stores in the late 1970s and early 1980s. The first units, ordered unseen, were delivered in November 1977, and rolled out to the stores the third week of December. The line won popularity with...
, and soon had versions for CP/M
CP/M
CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
and the IBM PC
IBM PC
The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
. Reference Software of San Francisco, CA, acquired Grammatik in 1985. Development of Grammatik continued, and it became an actual grammar checker that could detect writing errors beyond simple style checking.
Other early diction and style checking programs included Punctuation & Style, Correct Grammar, and RightWriter. While all the earliest programs started out as simple diction and style checkers, all eventually added various levels of language processing, and developed some level of true grammar checking capability.
Until 1992, grammar checkers were sold as add-on programs. There were still a large number of different word processing programs available at that time, with WordPerfect
WordPerfect
WordPerfect is a word processing application, now owned by Corel.Bruce Bastian, a Brigham Young University graduate student, and BYU computer science professor Dr. Alan Ashton joined forces to design a word processing system for the city of Orem's Data General Corp. minicomputer system in 1979...
and Microsoft Word
Microsoft Word
Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platforms including IBM PCs running DOS , the Apple Macintosh , the AT&T Unix PC , Atari ST , SCO UNIX,...
the top two in market share. In 1992, Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
decided to add grammar checking as a feature of Word and licensed CorrecText, a grammar checker from Houghton Mifflin
Houghton Mifflin
Houghton Mifflin Harcourt is an educational and trade publisher in the United States. Headquartered in Boston's Back Bay, it publishes textbooks, instructional technology materials, assessments, reference works, and fiction and non-fiction for both young readers and adults.-History:The company was...
that had not yet been marketed as a standalone product. WordPerfect answered Microsoft’s move by acquiring Reference Software, and the direct descendant of Grammatik is still included with WordPerfect.
Technical issues
The earliest writing style programs checked for wordy, trite, clichéCliché
A cliché or cliche is an expression, idea, or element of an artistic work which has been overused to the point of losing its original meaning or effect, especially when at some earlier time it was considered meaningful or novel. In phraseology, the term has taken on a more technical meaning,...
d, or misused phrases in a text. This process was based on simple pattern matching
Pattern matching
In computer science, pattern matching is the act of checking some sequence of tokens for the presence of the constituents of some pattern. In contrast to pattern recognition, the match usually has to be exact. The patterns generally have the form of either sequences or tree structures...
. The heart of the program was a list of many hundreds or thousands of phrases that are considered poor writing by many experts. The list of suspect phrases included alternative wording for each phrase. The checking program would simply break text into sentences, check for any matches in the phrase dictionary, and flag suspect phrases and show an alternative. These programs could also perform some mechanical checks. For example, they would typically flag doubled words, doubled punctuation, some capitalization
Capitalization
Capitalization is writing a word with its first letter as a majuscule and the remaining letters in minuscules . This of course only applies to those writing systems which have a case distinction...
errors, and other simple mechanical mistakes.
True grammar checking is more complex. While a computer programming language has a very specific syntax and grammar, this is not so for natural language
Natural language
In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...
s. Though it is possible to write a somewhat complete formal grammar
Formal grammar
A formal grammar is a set of formation rules for strings in a formal language. The rules describe how to form strings from the language's alphabet that are valid according to the language's syntax...
for a natural language, there are usually so many exceptions in real usage that a formal grammar is of minimal help in writing a grammar checker.
One of the most important parts of a natural language grammar checker is a dictionary
Dictionary
A dictionary is a collection of words in one or more specific languages, often listed alphabetically, with usage information, definitions, etymologies, phonetics, pronunciations, and other information; or a book of words in one language with their equivalents in another, also known as a lexicon...
of all words in the language, along with the part of speech of each word. The fact that natural words can take many different parts of speech greatly increases the complexity of any grammar checker.
A grammar checker will find each sentence in a text, look up each word in the dictionary, and then attempt to parse the sentence into a form that matches a grammar. Using various rules, the program can then detect various errors, such as agreement in tense
Grammatical tense
A tense is a grammatical category that locates a situation in time, to indicate when the situation takes place.Bernard Comrie, Aspect, 1976:6:...
, number, word order
Word order
In linguistics, word order typology refers to the study of the order of the syntactic constituents of a language, and how different languages can employ different orders. Correlations between orders found in different syntactic subdomains are also of interest...
, and so on.
It is also possible to detect some stylistic problems with the text. For example, use of the passive voice
Passive voice
Passive voice is a grammatical voice common in many of the world's languages. Passive is used in a clause whose subject expresses the theme or patient of the main verb. That is, the subject undergoes an action or has its state changed. A sentence whose theme is marked as grammatical subject is...
is criticized by popular style guides such as The Elements of Style
The Elements of Style
The Elements of Style , also known as Strunk & White, by William Strunk, Jr. and E. B. White, is a prescriptive American English writing style guide comprising eight "elementary rules of usage", ten "elementary principles of composition", "a few matters of form", a list of forty-nine "words and...
. Grammar checkers may attempt to identify passive sentences and suggest an active-voice alternative.
The software elements required for grammar checking are closely related to some of the development issues that need to be addressed for voice recognition software. In voice recognition, parsing can be used to help predict which word is most likely correct based on part of speech and position in the sentence. In grammar checking, the parsing is used to detect words that fail to follow proper grammar usage.
Recently, research has focused on developing algorithms which are capable of recognizing grammar
Grammar
In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...
errors based on the context of the surrounding words. Context-based grammar
Grammar
In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...
checkers appear in Microsoft Office 2007
Microsoft Office 2007
Microsoft Office 2007 is a Windows version of the Microsoft Office System, Microsoft's productivity suite. Formerly known as Office 12 in the initial stages of its beta cycle, it was released to volume license customers on November 30, 2006 and made available to retail customers on January 30, 2007...
, Google Wave
Google Wave
Apache Wave is a software framework for real-time collaborative editing online. Google Inc. originally developed it as Google Wave.It was announced at the Google I/O conference on May 27, 2009....
, NeuroGrammar, Grammarly, Ginger Software, and in Ghotit Dyslexia context spell and grammar checker tuned for people with dyslexia.
Criticism
As with other computerized writing aids such as spell checkerSpell checker
In computing, a spell checker is an application program that flags words in a document that may not be spelled correctly. Spell checkers may be stand-alone capable of operating on a block of text, or as part of a larger application, such as a word processor, email client, electronic dictionary,...
s, popular grammar checkers are often criticized when they fail to spot errors and incorrectly flag correct text as erroneous. The linguist Geoffrey K. Pullum has argued that they are generally so inaccurate as to do more harm than good: "for the most part, accepting the advice of a computer grammar checker on your prose will make it much worse, sometimes hilariously incoherent."