Linguistic Units & Grammatical/Syntactic Categories – Comprehensive Study Notes

Overview: The Architecture of Language

Language is structured hierarchically. Each higher-level unit is built from the units below it, much like bricks → walls → rooms → an entire house.

1. Morpheme → smallest meaningful form
2. Word → one or more morphemes
3. Phrase → word‐group acting as a single syntactic unit
4. Clause → phrase-group with its own Subject + Predicate
5. Sentence → one or more clauses that express a complete thought

Understanding the properties of, and relations among, these units underpins morphology, syntax, semantics, psycholinguistics, language acquisition, NLP and AI.

Morphemes

A morpheme is the minimal linguistic sign that carries meaning or grammatical function and cannot be subdivided further without loss of meaning.

Main Division

• Free morphemes – stand alone as words.
  • Lexical (content/open-class): nouns, verbs, adjectives, adverbs. New items can be coined (blog, selfie).
  • Functional (grammatical/closed-class): determiners, prepositions, conjunctions, pronouns, particles. Rarely admit new items.
• Bound morphemes – must attach to a host.
  • Derivational – create new lexemes or change word-class: happy → happi-ness, act → re-act, write → writ-er.
  • Inflectional – encode grammatical categories without changing class: walk → walk-ed, cat → cat-s. English has 8 inflectional suffixes ((-s, -ed, -ing, -en, -er, -est, 's, -s) for person/number).

Significance

• Explains spelling & pronunciation alternations (heal → health; electric → electricity).
• Essential for parsing, machine translation, spell-checking.

Words

A word is the smallest free unit that can occupy slots in syntax and convey meaning.

• Etymology ((\textit{etymon}+\textit{logia})) traces historical origin.

Structural Classes

Major Word-Formation Processes (English)

• Borrowing (guru, ballet)
• Compounding (credit-card)
• Blending (brunch, smog)
• Clipping (demo, lab)
• Back-formation (edit ← editor)
• Conversion/Zero-derivation (to email, to google)

Phrases

Phrase = group of words lacking its own subject–predicate, behaving as a single unit. Key features: no finite verb (except inside an embedded clause), headedness, internal flexibility.

Head & Modifiers

• Head determines syntactic category.
• Pre-/Post-modifiers expand or restrict meaning.

Major Phrase Types (English)

Clauses

A clause is a group of words containing (at least) a subject and a finite verb. Larger than a phrase, smaller than a sentence.

Independence

• Independent/Main clause – expresses a complete thought; can stand alone.
• Dependent/Subordinate clause – requires a main clause; functions as:
  • Noun Clause – What she wrote is fascinating.
  • Adjective / Relative Clause – The man who is wearing red…
  • Adverb Clause – Because it was hot, I drank water.
  • Coordinate Clause – linked by FANBOYS (and, but, or…).

Comparison Table

Syntactic Categories (Parts of Speech)

Lexical (Open-Class)

• Nouns – reference; sub-types: common, proper, abstract, concrete, mass, count, collective.
• Verbs – actions/states; transitive vs intransitive; linking vs auxiliary; argument structure.
• Adjectives – modify nouns; gradable, comparative, superlative.
• Adverbs – modify V/Adj/Adv; classes: manner, time, place, frequency, degree.
• Prepositions – mark spatial/temporal/logical relations; head of PP.

Functional (Closed-Class)

• Determiners – articles, demonstratives, possessives, quantifiers.
• Pronouns – personal, reflexive, reciprocal, interrogative, relative, indefinite.
• Auxiliary Verbs – primary (be, have, do); modal (can, may, must…).
• Conjunctions – coordinating, correlative, subordinating.
• Complementizers – that, if, whether.

Phrasal Categories & Representation

• Phrasal categories (NP, VP, PP, AdjP, AdvP) are built recursively.
• Labelled-bracketing and tree diagrams visualise hierarchy.

Example sentence

(S
   (NP (Det The) (Adj fat) (N cat))
   (VP (V sat)
       (PP (P on)
           (NP (Det the) (N mat))))
)

Structural ambiguity: She attacked the man with a knife → two parses (instrument v. attribute).

Cross-Linguistic Insights & Flexibility

1. Category universals vs language-specific realisation (e.g. grammatical gender in German vs natural gender in Sinhala).
2. Syntactic flexibility – in Chinese a single form chi can be noun ‘food’ or verb ‘eat’; English needs derivation (run → runner).
3. Implications – informs typology, L2 acquisition (article errors by Sinhala/Tamil speakers), NLP design.

Grammatical Categories

Number

• Core distinction {\text{singular},\;\text{plural}}.
• Some languages add dual (Arabic, Sanskrit) or trial.

Gender

• Grammatical gender (German: der Tisch MASC) vs natural/social gender (Sinhala lacks grammatical agreement).

Case (Classical 7-case model)

Person

1st (person speaking), 2nd (addressed), 3rd (about). Drives agreement.

Voice

• Active – subject agent (The cat chased the mouse).
• Passive – subject patient (The mouse was chased by the cat). Alters information structure, allows topicalisation.

Tense & Aspect

• Tense locates event in time (past / present / future).
• Aspect views event as complete or ongoing.
  • Perfective (completed) vs Imperfective / Progressive (ongoing).
  • English auxiliaries: have (perfect), be + V-ing (progressive).

Verb-Phrase Combination Patterns

Four basic chains (max 4 auxiliaries):

1. Modal + V ( can go )
2. Perfect = have + V_{en} ( _has eaten_ )
3. Progressive = be + V_{ing} ( _is eating_ )
4. Passive = be + V_{en} ( _was eaten_ )

Combined: may have been being tested.

Worked Example: Decomposing a Sentence

Sentence: “The sergeant ordered the slave to be thrown into the water so that he could have experienced the true danger of life.”

1. Morphemes – sergeant, order +-ed, slave, throw +-n, etc.
2. Words – the | sergeant | ordered | the | slave | to | be | thrown | into | the | water | so that | he | could | have | experienced | the | true | danger | of | life.
3. Phrases –
   • NP: the sergeant, the slave, the water, the true danger.
   • VP: ordered …, could have experienced ….
   • PP: into the water.
   • Clause: main + purpose clause (so that…).

Key Take-Aways

• Linguistic structure is hierarchical; mastery requires seeing the links across levels.
• Morphemes explain word formation; words combine into phrases whose heads determine category; clauses bring propositional force.
• Syntactic & grammatical categories (number, case, voice, etc.) regulate agreement and interpretation cross-linguistically.
• Representations (trees, brackets) reveal ambiguity and guide computational parsing.
• Comparative study and L2 research show both universals and language-specific flexibility, informing teaching, AI and theoretical models.

“When you know the parts and how they fit, you can build any sentence, in any language.”