Thanks. I am taking a French course. In a section on French imperfect and participles, I got a question wrong because of mistranslating open in this sentence. When I posted a question about my confusion why open was handled the way it was, I got a confusing answer about different ways of dealing with participles.
After looking at their explanation about participle forms in different tenses and the actual sentence, it occurred to me that open wasn't part of a compound verb at all, but was simply an adjective even though it was in a section on compound verbs. If it is an adjective modifying the door, in this sentence, then it is easy to see why my translation was wrong and how to correct it.
Mapping tenses across different languages is not always easy. Especially if you are primed to look for zebra compound verbs when you actually have a plain old present tense, verb to be followed by an adjective, horse.