Let's consider two versions of a sentence:
- You should brush your teeth before going to school but after waking up.
- You should brush your teeth before going to school after waking up.
My intuition is that option 1 is the only correct version of this sentence but I can't explain why the "but" is necessary? I suspect that there is some rule for joining multiple dependent clauses with an independent clause but I couldn't find any materials for that.