Third person

The person category representing everyone and everything other than the person(s) speaking and the person(s) spoken to. Practically all noun phrases are third person.

Examples are: he, she, it, they, the dog, my master, Mercury, beauty etc.

In English, the only non-third-person noun phrases are the first-person pronouns I/me and we/us and the second-person pronoun you.

Time adverb

An adverb that answers the question ‘when?’

Examples are: today, tomorrow, yesterday, always, once, soon, often etc.

An adverb phrase that does the same is a time adverbial.

Examples are: as soon as possible, next Wednesday, whenever you like.

To-infinitive

A traditional label for a sequence consisting of the particle to followed by an infinitive. For example, in Alice has decided to quit her job, the sequence to quit would be regarded as a to-infinitive.

Other examples are given below.

•That was a sight to see.

•The best thing to do now is to vanish. 

•Alice likes to read science fiction.

Uncountable noun

A noun which has no plural form and cannot normally be used with the article a/an.

Examples are: mud, rudeness, wheat, water, furniture etc. Uncountable (or mass) nouns are the names of materials, liquids, abstract qualities, collections and other things which we see as masses without clear boundaries, and not as separate objects.

Note that not all nouns are either simply countable or uncountable. Many nouns have both countable and uncountable uses, sometimes with a difference of meaning.