Foundations

Parts of Speech

Every word in a sentence belongs to a part of speech, such as noun, verb or adjective. Grammify labels each word twice: with a broad category and with a detailed tag. This page shows how to choose both labels, which is what the POS and Tags exercises ask you to do.

What you’ll learn

Explain why every word gets two labels: a coarse POS and a fine tag
Work out a word's category from the job it does, not from its form or ending
Label each word of a sentence with one of the seventeen coarse categories
Read a fine tag and say what it shows: number, tense, person or degree

Two labels for every word

The parser, the program that analyses every sentence in Grammify, gives each word two labels. The first is the POS, short for part of speech. It is a coarse (broad) category, one of seventeen that are used for many languages, Spanish included. The second is the TAG, a fine (detailed) label for English only. It comes from a standard set called the Penn Treebank tags.

The coarse label says what kind of word this is. The fine label adds details of form: number for nouns (fox, foxes), tense and person for verbs, and degree for adjectives and adverbs (heavy, heavier, heaviest).

Take they freeze, it freezes and it froze. All three verbs are VERB on the coarse scale, because the coarse label ignores form. On the fine scale they are VBP, VBZ and VBD. VBD marks the past. VBZ marks the present with a third-person singular subject, such as he, she or it. VBP marks the present with any other subject. After will, the verb is VB, the base form: it will freeze.

One sentence on the coarse scale

A (^DET)curious (^ADJ)fox (^NOUN)watched (^VERB)us (^PRON)quietly (^ADV).

…and the same sentence on the fine scale

A (^DT)curious (^JJ)fox (^NN)watched (^VBD)us (^PRP)quietly (^RB).

Compare the two rows; each scale has its own colours. On the fine scale, fox becomes NN, a singular noun, and watched becomes VBD, a verb in the past tense.

Working out a word’s category

The most common mistake is to decide from the word’s form or ending. In English, one spelling can belong to several categories: watch is a noun in a nice watch and a verb in they watch. The job the word does in this sentence decides its category.

1
Test the word
- A noun fits after the and usually has a plural: the watch, two watches.
- A verb can be put in the past or the future: they watch, they watched, they will watch.
- An adjective fits between the and a noun, and after is: the curious fox, the fox is curious.
- An adverb tells you how, when, where or how often: quietly, soon, here, never.
Find the word it describes
An adjective describes a noun. An adverb describes a verb, an adjective or another adverb. If the word describes nothing, it is probably neither.
Then add the detail for the fine tag
For a noun, ask two questions: is it singular or plural, and is it a name? A common noun is NN when it is singular and NNS when it is plural. A name is a proper noun: PROPN on the coarse scale, and NNP or NNPS on the fine one. For a verb, ask about its form: the base form is VB, the past VBD, the -ing form VBG, the past participle VBN, and the present VBP or VBZ.

A worked example: Diego waters the plants every morning. Two words have misleading endings. Waters ends in -s like a plural noun, and plants could be a verb, as in she plants trees.

The tests in step 1 decide. Waters can be put in the past (Diego watered the plants), so it is a verb. Plants comes after the, so it is a noun. Step 3 adds the details: waters is present with a third-person singular subject (VBZ), and plants is plural (NNS).

Diego (^NNP)waters (^VBZ, ringed)the (^DT)plants (^NNS, ringed)every (^DT)morning (^NN).

The seventeen coarse categories

The table lists all seventeen coarse categories, each with a short definition and examples. Each category has its own colour. The POS exercise uses the same colours, so a category looks the same wherever you meet it.

Every badge and name in the table is a link, and so is every tag in the list after it. Each link takes you to that category or tag on one of the Word Classes pages. There you will find how the parser decides, with example sentences for every category and every tag, even the rare ones.

The seventeen coarse categories, with examples
Category	What it is, with examples
NOUN Noun	A person, thing, place or idea. fox, courage, river
PROPN Proper noun	The name of one particular person, place or thing. Nina, Lisbon
PRON Pronoun	Takes the place of a noun. Possessives such as my are PRON too. she, us, my, everything
VERB Verb	A main verb: an action or a state. watched, freeze
AUX Auxiliary	A helping verb that adds tense, aspect, voice or modality. The linking verb be is AUX too. has, was, will, is
ADJ Adjective	Describes a noun. curious, heavy
ADV Adverb	Describes a verb, adjective or other adverb. quietly, never
DET Determiner	Comes before a noun and says which one or how many. a, the, this, every
ADP Adposition	A preposition: it links a noun or pronoun to another word. at, through
PART Particle	A small grammar word that fits no other category. to (before a verb), not, 's
SCONJ Subordinating conj.	Begins a dependent clause. because, whether
CCONJ Coordinating conj.	Joins two equal elements. and, but, or
NUM Numeral	A number, in words or in figures. three, 42
INTJ Interjection	An exclamation outside the grammar of the sentence. oh, hey
SYM Symbol	A sign that is not a word, such as $. The % sign is NOUN, not SYM. $, x (as in 3 x 4)
PUNCT Punctuation	A punctuation mark. The exercises skip it. . , ?
X Other	Anything that fits nowhere else, such as a foreign word. de facto

The Penn Treebank tags

These are the fine tags, and every button in the Tags exercise is one of them. They are grouped in families that mostly follow the coarse categories. The three adjective tags come first, then IN, then the four adverb tags, and so on. Tags in one family have similar colours, so NN and NNS look related but are not the same.

You do not need to memorise the list. A typical sentence uses five to nine tags, and the exercise offers only the tags that the sentence contains.

Quick check

In Omar was reading a novel., the word was is AUX on the coarse scale and VBD on the fine scale. Is one of these labels a mistake?
Answer
No. The coarse label names the word’s job: was helps the main verb reading, so it is AUX. The fine tag names its form: was is a past form, so it is VBD. The two labels answer different questions, and both are right.
In The farmers plant rice in May., is plant a noun or a verb? How can you tell?
Answer
A verb (VERB, VBP). It says what the farmers do, and it can be put in the past: The farmers planted rice in May. The same spelling is a noun in a plant, but here its job makes it a verb.
Give the coarse category of each word in Nina moved to Medellín last year.
Answer
Nina PROPN, moved VERB, to ADP, Medellín PROPN, last ADJ, year NOUN. There are two traps. Here to is a preposition, because a noun follows it; before a verb, as in to leave, it is PART. And last describes the noun year, so it is an adjective.
In Their aunt bakes bread on Fridays., bakes is VBZ. In The twins bake bread on Fridays., bake is VBP. What does each tag tell you?
Answer
Both are verbs in the present tense. VBZ adds that the subject is third person singular: their aunt is a she. VBP is the present with any other subject: the twins are a they. On the coarse scale, both verbs are simply VERB.

Key terms

Part of speech: A word’s class, decided by the job it does in its sentence: noun, verb, adjective, adverb and so on. Grammify uses seventeen of them, the coarse POS categories. One spelling can change class: The guards watch the gate. — a verb. My watch stopped at noon. — a noun.
See: Grammar Basics
POS (coarse): The coarse category, one of seventeen. They come from Universal Dependencies, a project that uses the same categories for many languages. This is what the POS exercise asks for. The kettle whistled. — DET, NOUN, VERB. She left quickly. — PRON, VERB, ADV.
See: Grammar Basics
TAG (fine): The Penn Treebank label, for English only. It adds the details of form that the coarse category leaves out: number, tense, person and degree. This is what the Tags exercise asks for. The kettle whistled. — DT, NN, VBD: a singular noun and a past-tense verb. Kettles whistle. — NNS, VBP.
Lemma: The dictionary form of a word: watched → watch, foxes → fox. Grammify records it for every word, but no exercise asks for it. The foxes watched us. has the lemmas the, fox, watch, we. She is running late. has she, be, run, late.
Morphology: In linguistics, the study of word forms. In Grammify it means the grammatical features that come with a word’s fine tag, such as Tense=Past or Number=Sing. Grammify records them for every word, but no exercise asks for them. She sings. — VBZ gives Tense=Pres and Person=3. They sang. — VBD gives Tense=Past.
See: Modal Auxiliaries · Tense

Practice on a real sentence

Label every word twice: first its coarse category in the POS tab, then its fine tag in the Tags tab. Be careful with the endings: one word ends in -s but is a verb, and one ends in -ed but is an adjective. A button can be used more than once; its number shows how many words still need it.

Loading the practice sentence…

Next: how the words of a sentence fit together in a diagram. Read Reed-Kellogg Diagrams first, for the traditional diagram that groups the words. Then read Dependency Parsing, for the tree that links each word to the word it depends on.