third conditional - if+past perf+would have+past participle
If you ________ (not/be) late, we _________(not/miss) the bus.
[ hadn't been ][ wouldn't have missed ]
If they _______ (go) to bed early, they ________ (not/wake) up late.
[ had gone ][ wouldn't have woken ]
If we _______ (not/go) to the party, we ________ (not/meet) them.
[ hadn't gone ][ wouldn't have met ]