The infinitive is the basic form of the verb. We can use it with or without the particle to, depending on the verb, noun, or the adjective it follows.
Rule 1: We can use to + infinitive to indicate the purpose or intention of an action, in the meaning of in order to or so as to.
Rule 2: We can use to-infinitive as the subject of the sentence. It is more common in formal writing than in spoken English.
Rule 3: We can use to-infinitive to indicate what something can or will be used for. In this care, it usually follows a noun or pronoun.
Rule 4: We can use to-infinitive to express judgement or make a comment.
Rule 5: We can use to-infinitive with verbs like ask, decide, explain, forget, know, etc. followed by question words where, how, what, who, and when.
Rule 6: We can use to-infinitive after adjectives.
Rule 7: We can use to-infinitive with the adverbs too and enough (placed before or after the adjective, adverb, or noun that they modify) to express the reasoning behind satisfaction or disappointment.
Quiz
1/4Choose the correct form of the verb. She wants ___ milk.