Why say
彼{かれ}らは私{わたし}の勉強{べんきょう}を手{て}伝{つだ}ってくれる
instead of
彼{かれ}らは勉強{べんきょう}を私{わたし}に手{て}伝{つだ}う
to say "they help me study"?
What does くれる do in the first sentence? Doesn't it mean "to give"?
Also, how do you say "They even said they would help me study" in Japanese?