A

abstract noun

An abstract noun is a noun that does not describe a physical object, for example philosophy. Contrast common noun.

 

 

accepter

An accepter is a program (or algorithm) that takes as input a grammar and a string of terminal symbols from the alphabet of that grammar, and outputs yes (or something equivalent) if the string is a sentence of the grammar, and no otherwise. Contrast parser.

 

active arc

An active arc is a structure used by a chart parser as it attempts to parse a sentence. It is derived ultimately from a rule of the grammar being used, and consists of:

• a name for the arc,
• a type - the phrasal category being sought,
• a list of found constituents, i.e. constituents required by a grammar rule
• a list of types of the constituents not yet found,
• a from position, indicating the position in the sentence of the start of the first found constituent, and
• a to position, indicating the position in the sentence of the end of the last found constituent.

The symbol→ is used to separated the type from the list of found constituents, and a dot is used to separate the list of found constituents from the list of types of constituents not yet found.

Example:

Here ARC2 is the name, NP is the type, DET1 ADJ1 is the list of found constituents, NOUN is the (single item) list of constituents not yet found, and the from and to positions are 0 and 2. This active arc would derive from the grammar rule NP → DET ADJ NOUN which says that an NP may be an DETerminer followed by an ADJective followed by a NOUN.

active chart

= chart (in a chart parser)

active voice

Sentences in English may be in active or passive form. The active form makes the one who is performing the action in the sentence (termed the agent in semantics) the grammatical subject. This serves to focus attention on the agent. Example: "John ate the pizza". The alternative, the passive voice, makes the thing acted on into the grammatical subject, thus focussing attention on that thing, rather than on the agent. Example: "The pizza was eaten by John." Many writers appear to believe that use of the passive seems more formal and dignified, and consequently it is over-used in technical writing. For example, they might write "The following experiments were performed" when it would be clearer to say "We [i.e. the authors] performed the following experiments."

Contrast mood, tense, and aspect.

ADJ

symbol used in grammar rules for an adjective.

adjective

An adjective is a word that modifies a noun by specifying an attribute of the noun. Examples include adjectives of colour, like red, size or shape, like round or large, along with thousands of less classifiable adjectives like willing, onerous, etc. In grammar rules, we use the symbol ADJ for the pre-terminal category of adjectives.

Adjectives are also used as the complements of sentences with verbs like "be" and "seem" - "He is happy", "He seems drunk".

ADJ is a lexical grammatical category.

adjective phrase

Adjective Phrase (or adjectival phrase) is a phrasal grammatical category. Adjective phrase is usually abbreviated to ADJP. They range from simple adjectives (like "green" in "the green grass") through short lists of adjectives possibly modified by an adverb or so (like "really large, cream" in "that really large, cream building") to fairly complicated constructs like "angry that he had been ignored" in "Jack was angry that he had been ignored". The longer adjective phrases are frequently take the form of an adjective followed by a complement, which might be a "that"+Sentence complement (as in "angry that he had been ignored"), or a PP complement or a "to"+VP complement.

The longer ADJPs are most often found as complements of verbs such as "be" and "seem". ADJP is a phrasal grammatical category.

ADJP

symbol used in grammar rules for an adjective phrase.

ADV

symbol used in grammar rules for an adverb.

adverb

An adverb is a word that modifies a verb, ("strongly", in "she swam strongly") an adjective, ("very", in "a very strong swimmer") or another adverb ("very", in "she swam very strongly").

Many adverbs end with the morpheme -ly, which converts an adjective X into an adverb meaning something like "in an X manner" - thus "bravely" = "in a brave manner". Other adverbs include intensifiers like "very" and "extremely". There are also adverbs of time (like "today", "tomorrow", "then" - as in "I gave him the book then"), frequency ("never", "often"), and place ("here", "there", and "everywhere").

ADV is a lexical grammatical category.

adverbial phrase

Adverbial phrases are phrases that perform one of the functions of an adverb. They include simple phrases that express some of the same types of concepts that a single adverb might express, such as frequency - "every week", duration - "for three weeks", time - "at lunchtime", and manner - "this way" ("Do it this way"), or "by holding his head under water for one minute".

Adverbial Phrase is a phrasal grammatical category. Adverbial phrase is usually abbreviated to ADVP.

ADVP

symbol used in grammar rules for an adverbial phrase.

agent

A AGENT is a case used in logical forms. It signifies the entity that is acting in an event. It normally corresponds to the syntactic subject of an active voice declarative sentence. In the logical form for a state description, the term EXPERIENCER is used for the corresponding entity. AGENTs appear in the frame-like structures used to describe logical forms: e.g. the following, representing "John breaks it with the hammer":

 

break1(e1,	agent[name(j1, 'John')]
	theme[pro(i1, it1)]
	instr(the<h1, hammer1>])

agreement

Agreement is the phenomenon in many languages in which words must take certain inflections depending on the company they keep. A simple case occurs with verbs in the third person singular form and their singular subjects: "Jane likes cheese" is correct, but * "Jane like cheese" and * "My dogs likes cheese" are not, because the subjects and verbs do not agree on the number feature. The name used in the lecture notes for the agreement feature is agr. The possible values of the agr feature are 1s, 2s, 3s, 1p, 2p, 3p, signifying 1st person singular, 2nd person singular, ..., 3rd person plural. Pronouns like "I" and "me" have agr=1s, "you" has agr={2s,2p} as it is not possible to distinguishsingular from plural in this case, and so on. Definite noun phrases like "the green ball" have agr=3s.

Allen

This refers to the book by James Allen, Natural Language Processing, second edition, Benjamin Cummings, 1995.