The infinitive is used without to after modal auxiliary verbs will, shall, would, should, can, could, may, might and must. It might rain later in the evening. (NOT It might to rain later in the evening.) I must go now.

Can infinitive be used without TO?

We use the infinitive without to after modal verbs can, could, may, might, will, shall, would, should, must: She can sleep in the guest room tonight. ... We also use the infinitive without to after let, make and (optionally) help: He lets us use some of his land to grow vegetables.

Does an infinitive always start with TO?

An infinitive will almost always begin with to. Exceptions do occur, however. For example, an infinitive will lose its to when it follows these verbs: feel, hear, help, let, make, see, and watch.