1) She has to study to present a very important test.
2) I don not have anything to say.
3) My teacher asked me to bring a long piece of homework.
4) They want to do karaoke sometime.
5) She does not want to go to the party.
It is important to highlight that an infinitive takes the particle TO plus a verb PLAY. So we get TO PLAY, TO GO, TO STUDY, TO JUMP, TO RUN, etc...
On the other had, we also have base form or bare infinitive. Eg., these ones do not take the particle TO. For example, PLAY, GO, STUDY, JUMP, RUN, etc...
