Usually, "while" indicates the passing of time and "whilst" is the same. So use while/whilst for time passing... Example: While/whilst I was walking down the street I saw a burglary. The use of whereas vs. while Whereas can be replaced with "on the other hand"; while can be replaced with "however". Whereas = conjunction in contrast or comparison with the fact that; taking into consideration the fact that. Examples: Bob was quite the rudest man I have ever met whereas John was a great guy. Bob was quite the rudest man I have ever met; on the other hand John was a great guy. While can be used as a conjunction meaning compared with the fact that; but Example: John is so polite while Bob is incredibly rude ..