Although there might be specific case, the general correspondence is as follows: 1. es gab = there was 2. es war = it/this was.

Normally, the direct equivalent for 'there was' is only 'es gab'. If you've heard 'es war', it's either a special construction for whatever follows, or it's a bad translation from English. :-) Can you give some examples for expressions where you've heard 'es war' for 'there was'?

It's hard to explain where the difference is. As Dirk already said, the translation of "there was" is "es gab". From the grammatical perspective, I cannot explain where the difference is, but I can give you some examples: - Es gab einen Unfall - Es gab Essen - Es war morgens - Es war toll Hope that helps! ;)