bare infinitive
The verb form without to.
A bare infinitive is the plain verb after a modal or after verbs such as make, let, help, see, hear, watch: can go, let him go, saw her leave. The to-infinitive keeps to: to go. After those verbs, do not insert to unless the sentence needs it for sense. Help may take either: help him pack or help him to pack.
Examples
Use She let the dog run.
Use They made him wait.
Avoid They made him to wait.