The term coordinate clause refers to one of two or more clauses of equal ‘value’ that make up a sentence. A coordinate clause does not function as a subject, object or complement in another sentence. It can stand alone to make a sentence by itself.

The term contraction refers to a short form in which a subject and an auxiliary verb or a verb and the word ‘not’ are joined together into one word. Examples are:

Compound

A compound noun, verb, adjective, preposition etc., is one that is made of two or more parts. The meaning of a compound is not always predictable from the meanings of its component parts.

A sentence in which special emphasis is given to one part (e.g. the subject or the object) by using a structure with it or what. The purpose of a cleft is to put the clefted element into focus. For example, starting with the sentence John wants a mobile phone, we can form an IT-cleft to focus either on John or on a mobile phone.
It is a mobile phone that John wants. (Focus on a mobile phone)
It is John who wants a mobile phone. (Focus on John)

An infinitive not preceded by to is a bare infinitive.

Examples are: write, say, tell, go, work etc.

A bare infinitive can immediately follow a modal auxiliary verb like must or will.

The label affirmative is applied to a statement which contains no negative item.
I agree. (affirmative)
I don’t agree. (negative)

A hidden agenda

When somebody has a hidden agenda, they have a secret motive for doing something.

• It would be foolish of us to believe everything that she says. I really suspect that she has a hidden agenda.