Paying attention to what mistakes German speakers consistently make in English is highly instructive as to how the equivalent constructions will be unintuitive to me in German. One that I've noticed across multiple languages is whether to make one or both verbs past tense or conditional in compound constructions, e.g.
"Didn't you went there yesterday?"
"I thought that will be helpful"
"I didn't know that will bother you"
These all tell me what the natural construction would be in the speaker's native language. I am always excited to notice such things.
