Is it possible to translate this sentence as "I was going to close the door"?
I know this is old and you probably have it figured out now, but you raise a good question, so I'm posting here for anyone else that gets confused by this sentence. Multiple comments below are wrong.
Short answer: No, use the imperfect tense to say "I was going..." "Iba a cerrar la puerta."
Long answer: I think you're combining tenses to get your translation. "Ir a + infinitive" does mean "going to..." and "fui" can be "I was" or "I went," as it's either "ser" or "ir," but not both at the same time. Keep in mind it's a preterite conjugation, so it's a specific event beginning and ending in the past. "Ser" makes no sense in this sentence, so you shouldn't think "I was" because "ser" gives us the wrong kind of "I was." That means "fui" is conjugated from "ir" in this sentence, so it means "I went." If i want to say "I was going," I say "iba."
Yes I think so. In present Duolingo showed that 'ir' could be is going like in "The boy is going to the market." 'El niño va al mercado.'
The two sentences have different meanings. I wonder how a person could make each meaning clear?
What about "I went to lock the door"? It wasn't accepted in my case, but is it technically correct?
"I went to close the door" or "I went to saw the door", that is "cerrar" or "serrar". In Spain we distinguish sounds /θ/ and /s/.
In the translation, it shows "I went out" but when I used this, it was marked wrong...
'To go out' is either 'irse' or 'salir'. Here the verb is just 'to go', 'ir'.