Why is て form used here?

Question

友達申請をしてくださって、ありがとうございます。

=>"Thank you that you have given the favor of doing a friend request."

What I expressed in my translation is something which usually gives me a lot of trouble when I try to express it in japanese. Until now, I wasn't aware that て-form is suitable in japanese for the phrase which is expressed through the "that-clause" in my translation. However, is the construction in the sentence in question always appropriate? For example: 車の修理をしてくださって、一万円をはらいます。

Is it formal/colloquial? Is it used in both written and oral communication?

Answer 1

Yes, te-form + くれて/くださって/していただいて + ありがとう(ございます) is basically Thank you for ～. In general, this te-form is denoting a reason, and this is explained in this article. It's not particularly formal nor casual, but in very formal situations, you need more formal wordings (something that corresponds to "I would like to express my deepest gratitude" rather than "Thank you"), anyway.

「車の修理をしてくださって、一万円をはらいます」 is wrong, and the reason is explained in the article above, too. It's wrong because it contains the speaker's will in the latter half of the sentence.

Answer 2

Do you know about the structure, してくれて ありがとう? It's how you thank someone for doing something for you. くださる is just the higher form of くれる so the speaker is trying to be more respectful. I don't think it equates to "that", more like "for". Thanks for being my friend, thanks for sending me a friend request. No, you can't use it like in your sentence. This is practically a set phrase.