use to + verb use for + noun/gerund I used it every day for research. I used it every day for doing research. I used it every day to do research.

I think we use " for+ nouns and to +infinitive verbs So if" research is used as a noun, for is correct. Also, for + ING is used when the subject is an object and you want to say its use.for ex.the hammer is used for nailing the sign to the post. I hope it helps

I Guess both, but it depends of the rest of the sentence. But hey, i'm still learning too!