Conjunction list

We use both when and while as subordinating conjunctions to introduce adverbial clauses of time.

They mean during the time that and indicate that something is or was happening when something else occurred:

• The prisoners escaped when / while the prison warders were eating their lunch.
  
• When / While the prison warders were eating their lunch, the prisoners escaped.

Note that we can also use as and whilst in the same way, although they sometimes sounds more formal or literary

• As the sun went down, I sipped a rum and coke on the balcony.
  
• I sipped a rum and coke on the balcony whilst the sun went slowly down on the horizon.

Note that during, which also introduces a longer period of time, is a preposition which is use with a noun or noun phrase:

• I first met my future wife during my stay in Casablanca.
  
• I first met my future wife while I was staying in Casablanca.

when not while

We use when, not while, to talk about something that occurs at the same time as a longer a

is while a conjunction yes or no

is while a conjunction examples