O futuro do passado (would, was going to)

Para falar de algo que estava no futuro, visto de um ponto do passado, os tempos do futuro recuam: will → would, am going to → was going to. É o “ia fazer” e o futuro do pretérito do português.

forma	uso	exemplo
would	previsão, promessa, discurso indireto	I knew she would love it.
was / were going to	plano ou intenção, muitas vezes não realizado	We were going to call, but we forgot.
was / were -ing	compromisso marcado	He was nervous: he was flying the next day.
was / were about to	algo muito próximo	I was about to leave when the phone rang.

Observações

Muito comum no discurso indireto: She said she would help.
was going to muitas vezes indica um plano que mudou: I was going to study, but I watched a film instead.
was to (formal) = estava planejado ou destinado: He was to become president.

Exemplos

I thought it would be easier.Achei que ia ser mais fácil.
They were going to get married in June.Eles iam se casar em junho.
She told me she was leaving on Friday.Ela me disse que ia embora na sexta.
We were about to give up when we found it.Estávamos prestes a desistir quando o encontramos.
I didn’t know she would be there.Eu não sabia que ela estaria lá.

Erros comuns

✗ I thought the test will be easy.✓ I thought the test would be easy.Visto do passado, o futuro recua: will vira would, como o “seria” do português.
✗ We are going to visit you yesterday, but it rained.✓ We were going to visit you yesterday, but it rained.Para um plano passado que não se realizou, usa-se was / were going to.
✗ I was about leaving when you called.✓ I was about to leave when you called.O “estava prestes a sair” do português corresponde a was about to leave, com to + forma base.
✗ I didn’t know you will be at the meeting.✓ I didn’t know you would be at the meeting.Depois de um verbo no passado como didn’t know, o futuro recua para would.
✗ We was going to buy a house.✓ We were going to buy a house.Com we, o passado de be é were: were going to.