Originally Posted by
ac220 Он решил, что пойдёт домой. He decided to go home.
Он не решил идти ли ему домой. He didn't decided if he would go home.
In the first sentence, isn't the situaion, as defined by the perfective verbs, such that he is where he is now, but will now go home? The English sentence is more ambiguous, it could be talking about a completely past event, but пойдёт implies to me that he is going to go home now - the decision has just taken place.
The second English sentence is not grammatically correct (didn't decided). If the Russian sentence applies to a situation fully in the past, it would be like this: (When I met him on the party last week) he hadn't decided (yet) whether to go home. I suppose it could also be applied to someone who is at a party now and has not decided so far whether he should go: he hasn't decided (yet) whether to go home. Or does решил imply otherwise?
'Whether to go home' can be replaced by 'whether / if he should go home' in both variants, but don't use 'if' and 'would' in the same clause.
Alternatively the sentence could also mean 'he failed to decide / didn't decide...' as in 'someone else decided for him'. Oh my, the mind boggles...
Robin