How to study IELTS writing 4

How do you use and, or, but, so or because? I used them like that.
EX) I bought an umbrella. Because it was rain yesterday.
However, if you write this, you can find error of consider revising. I didn’t understand what this error said, but I know how to use them now.

どうやってand、or、so、becauseを使っていますか？私は上のように使っていましたが、これだとWordで再考が必要とエラーになるんです。でもずっとなぜかわからなかったのですが、最近ようやくわかりました。Writingの際は以下のように使いましょう。

How to use and, or, but, so, because
1. I like pasta, and I always eat pasta. 　○
And I always eat pasta, I like pasta. 　×
2. I will stay home, or I will go out. 　○
Or I will go out, I will stay home. 　×
3. She works at school, but she wants to quit.　○
But she wants to quit at school, she works there.　×
4. I painted the wall just now, so you don’t touch it. 　○
So you don’t touch the wall, I painted it just now. 　○
5. I bought an umbrella, because it was rain. 　○
Because it was rain, I bought an umbrella. 　○

You can change only using so and because. And, or and but don’t change. I think learning English in Japan isn’t useful.

センテンスをチェンジできるのはSoとBecauseだけということになります。andやor、butはだめ。でもあくまでもAcademic writingの場合NGなのであって、話し言葉はもちろんOKです。日本の英語教育もこういうのを教えてほしいなー。