Catalan builds the near future with anar a plus an infinitive, but only in the forms that are not the plain past: vaig a dinar is ambiguous, so speakers prefer the plain present or penso plus infinitive for plans. Remember that vaig plus a bare infinitive is a PAST tense.
Examples
- Demà dinem amb els avis.
- Tomorrow we are having lunch with our grandparents.
- Penso anar al cinema aquest cap de setmana.
- I am thinking of going to the cinema this weekend.
- Ahir vaig anar al cinema.
- Yesterday I went to the cinema.
The mistake to avoid
Vaig anar is I went, not I am going - this is the commonest Catalan trap for Spanish speakers.
Where this fits in
Aficions i temps lliure, Catalan A2: Talk about hobbies, likes and dislikes, and free-time plans.