| Adjective | Qualifies a noun: grey, slow, abstract |
| Adverb | Qualifies a verb (i.e. describes how something is being done), adjective, or other adverb: slowly, hardly |
| Aspect | The grammatical expression of an action’s relation to time: simple, progressive, perfective, nonperfective |
| Case | Grammatical category applied to nominals to classify their syntactic functions, in some languages marked by inflexion: der, den, dem, des |
| Closed word class | A part of speech to which no new words are regularly added: article, preposition, auxiliary verb |
| Cognitive grammar | An approach to linguistics that understands language as an abstract symbolic system directly rooted in the same cognitive processes used for other thought processes and thus not routed through a syntactic subsystem as proposed by generative grammarians |
| Conjunction | Defines the relationship between two clauses: and, because |
| Function word | A word with mainly grammatical reference: article, pronoun, preposition, auxiliary verb, conjunction |
| Gender | Division of (some) nominals into the classes feminine, masculine, and neuter |
| Grammaticalization | The adaptation of a lexical item into a grammatical element (e.g. dummy do) |
| Generative (transformational) grammar | A linguistic model postulating an innate set of syntactic rules from which all linguistic utterances are generated, involving a transformation from an underlying deep structure to the apparent surface structure |
| Interjection | Isolated utterance with no syntactic connection to the surrounding content |
| Lexical word | A word referring to concepts outside of language: noun, (non-auxiliary) verb, adjective, adverb |
| Modality | Grammatical expression of possibility, likelihood, or necessity |
| Mood | Verbal category expressing whether an utterance is an assertion of fact (expressed by the indicative mood), possibility or indirect assertion (subjunctive), or command (imperative) |
| Nominal | A noun, pronoun, adjective, or article |
| Noun | Someone or something involved in the action |
| Number | The grammatical expression of singularity or plurality |
| Numeral | Part of speech mathematically quantifying nominals; divided into cardinal (five) and ordinal (fifth) numerals |
| Open word class | A part of speech to which new words are still regularly added: noun, adverb |
| Part of speech | Word class, by function |
| Phrase structure rules | A set of rules for parsing syntactic structures, defining the constitution of phrases with a view to finding structural correspondences across languages: S → NP VP |
| Preposition | Defines the relationship between two or more nominals: in, from |
| Pronoun | A word standing in for a noun |
| Tense | The grammatical expression of an action’s point in time: present, past/preterite, future |
| Verb | Action word: describes what is being done |
| Voice | Verbal category expressing whether a construction is active or passive |
| X-bar Theory | A model of phrase structure postulating an element X̄ (commonly written X') governing the head and optional complement of each phrase |