Are both options correct and formal? If so, which one is preferable?
1: It would happen if we don't act against it
2: It would happen if we don't act against
Many thanks!
Both are incorrect
It will happen if we don't act against it
It will happen if we don't act.
We use will:
to express beliefs about the present or future to talk about what people want to do or are willing to do to make promises, offers and requests.
would is the past tense form of will. Because it is a past tense, it is used:
to talk about the past to talk about hypotheses (when we imagine something) for politeness.
What would happen if we don't act? (hypothesis)
Ref British Council