* Translation It rained a lot yesterday. Even so, I still had to buy the things that my mother wanted me to buy, -> 비가 많이 왔어요. 그래도 나는 엄마가 사기를 원하는 것들을 사야 했어요. This is the 'exact translation' of the english sentence. However, though this sentence makes sense, it is a bit wierd to sentence to say out loud in Korean. So, I suggest a different formation of the sentence. 1. It rained a lot yesterday. Even so, I still had to do an errand for my mom, because she needed things. (*errand = 심부름 / do an errand = 심부름을 하다.) -> 어제 비가 많이 왔어요. 그래도 엄마가 필요한 것들이 있어서, 나는 엄마를 위해 심부름을 해야 했어요. -> 어제 비가 많이 왔어요. 그래도 나는 심부름을 해야 했는데, 엄마가 필요한 것들이 있었기 때문이에요. -> 어제 비가 많이 왔어요. 그래도 나는 심부름을 해야 했어요. 왜냐하면 엄마가 필요한 것들이 있었기 때문이에요. 3. It rained a lot yesterday. Even so, I still had to buy things, because my mom needed them. -> 어제 비가 많이 왔어요. 그래도 엄마가 필요한 것들이 있어서, 나는 그것들을 사야 했어요. -> 어제 비가 많이 왔어요. 그래도 나는 물건들을 사야 했어요. 왜냐하면 엄마가 그것들이 필요했기 때문이에요. These two are the sentences that you can use similar to your sentence but a bit more natural. (continue)

(continue) But my final suggestions are.. 1. It rained a lot yesterday. Even so, I still had to do an errand for my mom, because she said she needed things. (*errand = 심부름 / do an errand = 심부름을 하다.) -> 어제 비가 많이 왔어요. 그래도 엄마가 필요한 것들이 있다고 해서, 나는 엄마를 위해 심부름을 해야 했어요. 2. It rained a lot yesterday. Even so, I still had to buy things, because my mom said she needed them. -> 어제 비가 많이 왔어요. 그래도 엄마가 필요한 것들이 있다고 해서, 나는 그것들을 사야 했어요. These two. It is a bit more complicated sentences than the upper ones that I suggested first, since it has '-다고 해서' phrase. However, it sounds a lot more natural and more 'Korean' like sentence when the natives hear. But if the final two suggestions are too over your level, the first two suggestions are also can be applied as a 'natural' way to say setences that you asked. Hope it can be a help. : )

For the first sentence, you'd probably want to say something like, "어제 비가 많이 왔어요." It sounds more natural and I have been corrected many times by Koreans to say it similar to that. As for the second sentence (this is mostly my opinion), to make it sound more natural you could say, "그래도, 엄마는 원하는 것을 아직 있었으니까 내가 가게로 사러 갔어요." It's not simpler and probably could be said simpler, but I have heard Koreans say this before. I hope that this helps.

For the first sentence, you'd probably want to say something like, "어제 비가 많이 왔어요." It sounds more natural and I have been corrected many times by Koreans to say it similar to that. As for the second sentence (this is mostly my opinion), to make it sound more natural you could say, "그래도, 엄마는 원하는 것을 아직 있었으니까 내가 가게로 사러 갔어요." It's not simpler and probably could be said simpler, but I have heard Koreans say this before. I hope that this helps.