whereas
The French word 'tandis que' is used to introduce a contrast or comparison. It is often translated as 'whereas' in English. However, unlike 'whereas', 'tandis que' can also be used to introduce a concession or a simultaneous action. For example, 'Tandis que je travaillais, il a joué dehors' translates to 'While I was working, he played outside'.
While you were sleeping, I finished the work.
This sentence uses 'tandis que' to describe simultaneous activities. It is saying that while one person was sleeping, another was working.
While I love pizza, my brother hates it.
Here, 'tandis que' is used to express a contrast between two things. In this case, the love the speaker has for pizza versus the dislike their brother has.
As the sun was rising, we began our journey.
In this example, 'tandis que' serves to depict the occurrence of two events at the same time, specifically the rising sun and the start of a journey.