A finite clause can be a main clause or a subordinate clause. It must have a verb to show tense.
A non-finite clause is a subordinate clause that is based on a to-infinitive or a participle. It contains a verb that does not show tense, which means it does not show the time at which something happened. There are three types of nonfinite clauses.
a) To-infinitive clause
In this clause, the verb comes after the word to.
b) Present participle clause (or –ing clause)
In this clause, the verb ending in – ing is used.
c) Past participle clause
In this clause, the past participle form of the verb is used.
A subordinate conjunction is often used to begin a non-finite clause. The subordinate conjunctions used here are if, unless, though.