Adjective 2026-11-05
An adjective is a part of speech characteristically used to express properties and modify nouns. It can also occur in predicative constructions, as in
The cube is red. Its classification depends on its grammatical behavior, beyond whether its meaning sounds descriptive.[ref]Universal Dependencies annotation guidelines. ADJ, Definition, predicative use and Nouns vs. Adjectives
In an original simple formal semantics, let red objects form and cubes form . The expression
red cube can denote the intersection . This illustrates how an adjective can contribute a property to a noun phrase, while leaving the grammatical classification distinct from that particular semantic rule. CoNLL-U 2026-11-05
CoNLL-U is a plain-text format for exchanging Universal Dependencies linguistic annotation. A word line has ten tab-separated fields: identifier, form, lemma, universal and optional local part of speech, features, basic head, basic relation, enhanced dependencies and miscellaneous information. Blank lines separate sentences; hash-prefixed comments can describe each sentence.[ref]
CoNLL-U Format in Universal Dependencies. opening format specification and ten-column field definitions
An original two-word example, with literal tab separators, is:The first word depends on word two as its subject; word two is attached to the notional root numbered zero. Underscores indicate unspecified values. A saved sentence ends with its blank separator, including at the end of a file.
# text = Birds fly
1 Birds bird NOUN _ Number=Plur 2 nsubj _ _
2 fly fly VERB _ _ 0 root _ _
The specification also requires UTF-8 text with NFC Unicode normalization and LF line endings. Range identifiers represent multiword tokens and decimal identifiers represent empty nodes under additional rules. Consequently, counting ten columns is useful but insufficient for validating every CoNLL-U record.
Lemma (linguistics) 2026-11-05
A lemma is a conventional citation form used to represent a lexical entry or a set of related grammatical forms. It differs from a lexeme, the abstract vocabulary item being represented, and from an arbitrary truncation of a word's spelling. The convention is language-specific.[ref]
Morphology: General Principles in Universal Dependencies. Lemmas, canonical dictionary form and language-particular conventions
In a simple English analysis,
walks, walked and walking can be assigned the lemma walk. The Universal Dependencies guidelines also distinguish inflection from derivational morphology: organizations has citation form organization, not organize or organ.Context can be needed before the citation form is chosen. The spelling
saw can name a tool or occur as a past form of see; a process that uses spelling alone cannot settle every such ambiguity. Recording the part of speech, intended word sense and the original occurrence makes a text corpus analysis more reproducible than retaining only the normalized label. Lexical database 2026-11-05
A lexical database organizes information about the lexemes of a language. It can record forms, part of speech, definitions, word senses, examples and relationships among entries. A database representation makes these items separately identifiable and queryable rather than treating an entire entry as one unstructured string.[ref]
Lexical Database in the SIL Glossary of Linguistic Terms. Definition and Discussion, entry contents and sense-specific information
For a toy design, an entry for
bank can link to distinct word sense records for a financial institution and a river margin, each with an example sentence. A form record for banks can refer to the relevant entry without requiring duplicated definitions. Spelling is consequently an inadequate unique identifier: different lexical analyses can involve the same written form.A lexical database can also connect entries to attested uses in a text corpus, as in FieldWorks Language Explorer. The stored relations support searches and revision, but the linguistic annotation still represents an analysis whose evidence must be retained.
Linguistic annotation 2026-11-05
Linguistic annotation adds explicit analytical information to language data, such as word boundaries, part of speech, grammatical number or syntactic dependencies. The original text and the assigned labels are distinct: an annotation records an analysis under stated conventions, rather than being an uninterpreted observation.
In the sentence
Birds fly, one analysis assigns the lemma forms bird and fly, the categories noun and verb, and a subject relationship connecting the first word to the second. Universal Dependencies represents such information in CoNLL-U, separating word forms, lemma forms, grammatical features and dependency fields.[ref]CoNLL-U Format in Universal Dependencies. ten-column format, FORM, LEMMA, UPOS, FEATS, HEAD and DEPREL
Keeping those layers separate permits a revised grammatical analysis without silently changing the underlying recording. It also makes disagreement inspectable: two annotators may agree on the text but assign different categories. A reusable annotated text corpus therefore needs its conventions and ambiguous cases documented alongside the labels.
Noun 2026-11-05
A noun is a part of speech whose members commonly name entities or concepts and head noun phrases. Meanings alone do not supply a complete classification: a noun can name an event or property as readily as a physical object. Distribution and inflection provide additional grammatical evidence.[ref]
Universal Dependencies annotation guidelines. NOUN, Definition and examples including abstract nouns
For example,
explosion names an event, but behaves as a noun in the explosion and two explosions. Its connection with an event does not make it a verb; compare The shell exploded. Likewise, redness is a noun even though it names a property associated with the adjective red.In Universal Dependencies, the tag
NOUN is reserved for common nouns, with PROPN used for proper nouns. That distinction matters when reproducing an analysis: a count of every traditionally named noun is not necessarily a count of only tokens tagged NOUN. Part of speech 2026-11-05
A part of speech is a grammatical word category identified by patterns of distribution, combination and, where relevant, inflection. Categories such as noun, verb and adjective help describe what an expression can do in a construction. Meaning is evidence, but a rule equating a category with one broad kind of meaning is insufficient.
For example,
record is a noun in the record and a verb in record the result. The same spelling can therefore require different labels when its context changes. A computational annotation scheme must state whether it assigns categories to lexical entries, individual occurrences or both.[ref]Morphology: General Principles in Universal Dependencies. Part-of-Speech Tags, context, prototypical usage and category distinctions
Universal Dependencies separates a broad part of speech label from additional grammatical features. Two forms can share the label
NOUN while differing in grammatical number. Keeping category and features distinct makes an analysis of a text corpus reproducible without multiplying category labels for every possible form. Universal Dependencies 2026-11-05
Universal Dependencies is a framework for comparable grammatical annotation across languages. It combines part of speech labels, morphological features and typed syntactic dependencies, while allowing documented language-specific choices. The framework supplies a common representation rather than a claim that all languages express every distinction identically.[ref]
Universal Dependencies annotation guidelines. project introduction and Morphology: General Principles, representation layers
For
Birds fly, a compatible analysis identifies Birds as a noun with plural grammatical number, gives it the lemma bird, and links it to fly with the subject relation nsubj. These are distinct annotation decisions: changing a lexical convention need not require changing the sentence's dependency structure.Basic dependencies form a rooted tree, whereas an enhanced representation can contain additional relations and need not remain a tree.[ref]
Universal Dependencies annotation guidelines. Syntax: General Principles, basic versus enhanced representation
Keeping the layers explicit helps compare parser output and manually analyzed text corpus resources. A valid interchange file and an empirically justified grammatical analysis remain different achievements. Verb 2026-11-05
A verb is a part of speech that commonly organizes a clause, specifying relationships among its participants and contributing an event or state description. Forms of a verb may express grammatical tense, grammatical aspect or grammatical agreement, though the mechanisms differ across languages.[ref]
Universal Dependencies annotation guidelines. VERB, Definition and distinction between main and auxiliary verbs
Compare
Rin sleeps with Rin opens the box. The second construction contains an object in addition to its subject; knowing a verb includes knowing how it combines with other expressions. Calling verbs “action words” misses examples such as know, which describes a state.An annotation scheme must also define its boundaries. Universal Dependencies assigns main verbs the label
VERB while distinguishing auxiliary uses with AUX. Thus a traditional grammatical description and a particular computational tag inventory need not draw every boundary identically. Stating the scheme makes category counts in a text corpus interpretable. WordNet 2026-11-05
WordNet is a lexical database that represents English word senses through synsets connected by labeled relationships. It groups meanings by part of speech, while keeping different meanings of the same written form distinct. Its organization therefore supports queries about concepts rather than spelling alone.[ref]
WordNet: A Lexical Database for English. About WordNet and Structure
For a toy information-retrieval task, suppose an annotated query uses the financial sense of
bank. Expanding it with terms attached to a river-margin sense would introduce irrelevant results even though the spelling matches. A sense-aware representation supplies the distinction needed to avoid that error; a separate method still has to choose the intended sense from context.WordNet also records relations such as hyponymy, connecting more specific concepts to broader ones. Following a labeled relation answers a different question from finding another member of the same synset.[ref]
WordNet: A Lexical Database for English. Relations, super-subordinate links
Neither neighborhood nor shared spelling guarantees that two expressions can replace each other in every sentence.