If they had known about the traffic, they would have taken a different route.

Translation language

Sentence

Narrator

If you know about potential traffic delays, you should plan an alternate route.

I always check traffic conditions before leaving, so I avoid delays.

Did they check the traffic report before setting off?

If there had been a traffic jam, we would have been late.

Had they been aware of the traffic congestion, an alternative route would have been selected.

If they'd known about the traffic, they would have gone a different way.

They would have taken another road if they knew about the traffic.

Past perfect tense indicating prior knowledge.

Past conditional expressing a hypothetical action.