-"since":
1.Since we've helped the homework, are right
De cand ne ajutam la teme,sunt corecte.
2.Since I've been injured, I've never had an accident.
De cand m-am accidentat,nu am mai avut niciun accident
-"for":
1.I bought a gift for my grandfather.
Am cumparat un cadou pentru bunicul meu.
2.For mum, I will do everything.
Pentru mama ,voi face totul.
Sper ca te-am ajutat !!!