"How have you entered my room?"
Übersetzung:Wie bist du in mein Zimmer gekommen?
In English, the expression is about a specific detail and so would not be normally done in the present perf. tense. Normally, "How did you enter my room?"
"Wie kamt ihr in mein Zimmer" (one M) would be correct.
Though (at least to my ears) Perfekt ("seid...gekommen"/"bist...gekommen") sounds more natural in this case.
this example does not allow 'gehen' whilst similar earlier example ONLY allowed 'gehen' and rejected 'kommen' - is it to do with the query here asking about the 'method' of entering the room rather than the 'action' alone - an explanation of the different ways of saying 'enter' in German would be very much appreciated!