"My mother and my father went to eat soup."
Translation:Mi madre y mi padre fueron a comer sopa.
I doubt it. As yuo might have seen in other sentences like this that use fui , fue or fueron this sentence structure is no does not prove itself there in your terms. However, what I have noticed is here "to" for which "a" is used is for one action leading to another action. However the mistake I did was , I considered the "infinitive to" in comir for that directional indicator . My fault !
That isn't completely true. "a" has many Spanish meanings that isn't always translated to English. Like in this case it is because you are going to do something. Ex: Voy a comer = I'm going to eat Fui a comer= I went to eat
DL isn't smart enough to make that distinction - it's looking for a particular phrase (mother and father), and only extends that to recognise other valid phrases (like parents) if it's updated. If you think it's a valid translation you need to tell them.
Personally I think you're on shaky ground... You're right, Mother and Father is broadly equivalent to "parents", but if the English sentence uses the words Mother and Father, IMO the sensible thing would be to translate this to "madre y padre".
I hope non-native speakers will not be encouraged to think that the use of "went to eat" is a natural equivalent of a "future in the past" ."Went to eat" would only be said if it expressed a special intention "They went to the restaurant to eat its famous soup." I am not a professional linguist, but someone who has been hearing and listening to English for 75 years since birth. The future formed by go + infinitive" is always the continuous form "I am going to...." .We don't say "I go to..." as a future. "I go to church" means "I regularly attend worship." "I am going to church" means I am on my way there or about to set off. "They were going to eat soup, but he had a heart attack on the way" If this is not a case of another way of expressing future in the past, I wonder if the meaning of the strange English would be conveyed better by "fueron para comer sopa".
I'm not sure what you are advising here exactly. "Went" + infinitive is not strange English to me.
"Where are your parents?"
"They went out to eat some soup." "They went to hear a concert." "They went to buy some food." "They went to find some new drapes at the store."
it's difficult to tell out of context, but in this case is "went to eat" simply meant to imply travel... for example they specifically went to a particular restaurant to eat the soup? I'm guessing they've used this expression to reinforce the lesson from the previous section that IR and SER have the same conjugation in the preterite.