saying "for" in korean...?
How would you say this kind of "for" in korean: "for my birthday i got a present." or "For christmas we had several meals." "For breakfast i had a glass of milk" i provided easy sentences on purpose to focus on the"for" that i'm talking about. I've seen (으)로 used in some cases but i just guessed that it means "for" , p.e. "생일 선물로 신발을 받았어" but whenever i googled the usage of (으)로 no one mentioned that it can be used to create the meaning of "for". i am aware of all the other meanings (으)로 has btw. in conclusion i'm unsure if (으)로 can be used to say "for" aswell
"For" in English covers a lot of uses. "For" can mean "in order to", "for the sake of [something/someone]", "for a duration of time", and "reason / because".
Now let me first cover 으로. 으로 technically means "by means of" (like 손으로 = by hand). So when you say 점심으로, it means "by means of lunch", which simply translates to "for lunch". Sounds kind of weird in English to use "by means of", doesn't it? Anyways, when you say "for [meal]" in Korean, you use 으로.
But of course 으로 is not the only translation of "for". There are many more. AshDan143 has already mentioned 위하다. This literally means "for the sake of". As in, "I wrote this song for (the sake of) you." Which, in Korean, would be, 나는 너를 위해 이 노래를 썼어. It also means "in order to", as in "I go to school (for studying / in order to study)." = 저는 공부하기 위해 학교에 가요.
Now let me cover your given sentences:
For Christmas, ... = 크리스마스에 ...
It would be more natural to use 에 here. In English we might say, "What are you doing for Christmas?", but we typically don't really mean "What are you doing for the sake of Christmas?". We usually just mean, "What are you doing on Christmas?" Hence, 에 is better than 위해. Take the song, "All I Want For Christmas Is You" -- the lyric, according to here, is 내가 크리스마스에 원하는 건 오직 당신 뿐이에요.
Regarding the sentence "for my birthday I received a present": There are two ways I might interpret and translate this: "As for my birthday, I received a present." = "내 새일은 선물을 받았어요." Or, just simply, Koreans might cut to the chase and say, "I received a birthday present". = "생일 선물을 받았어요." Notice that when you say "for my birthday" in English, you really are not saying "for the sake of my birthday". You're just talking about your birthday in general as a topic, hence no 위하다. (Though, if you really do mean "for the sake of my birthday", then you could use 위하다.)
You didn't really ask for this, but I'll talk about it briefly anyways.
In English we might say, "Thank you for ... [something]". This uses something different entirely: 서. In Korean, you would say the [something] first, then 서 then 감사합니다. For example, thank you for the birthday present: 생일 선물 주셔서 감사합니다. (This 서 is the cause and effect usage.)
Anyways, there are many ways to say "for" in Korean, which in English is encompassed all by one word. I didn't include some of the ways just so that things wouldn't get too confusing. I also probably haven't learned all the ways either. I hope you check out this video for more information. If I missed anything or anything is misinformation, anyone can feel free to correct me. I hope this was helpful.
I believe the verb you're looking for you is "위하다". "난 생일이 위해서 선물을 받았어요."
My Korean is a bit rusty, so please have a trusted source verify that.
Also, be careful of looking for direct translations. Many times, it's impossible from English to Korean or the other way around.