When and while conjunctions are used to join two different actions in the same period of time . “While” is used to express two different actions at the same time; whereas, when is used for two actions in sequence with minimum time gap.
Use of when
•When is used to refer a period of time. It connects two different actions in a same tense.
Suppose, first action is in the present, then other shouldn’t be in the other then present.
Examples of when
•It was the time of tension and insecurity when the world divided into two poles.
•He used to visit national parks when he was in the Kenya.
•When we visited tribal regions, we worked for tribal cause.
In all the three examples, we have seen that when is generally used to show two incidents in the same time.
•When is used to express actions in a sequence with minimum gap.
•When the bus arrived, the passengers had already left the bus stop.
•We had already covered the ground when it started raining.
•When they declared ceasefire, thousands of people had been killed.
These examples clearly highlight two incidents, happening one after another with minimum time gap.
Here, one is simple, whereas other is in the perfect past.
•For the future tense actions, simple present is used. “Will” is not used in the when clause.
•I will assist you when I finish job.
•Temperature will come down when the carbon emissions decrease.
•The situation will become serious when the rain delays.
Here, when is used like conditional conjunction. It is used to join two interdependent incidents in the sequence.
•Generally, when is preferred in the simple tense instead progressive. It is also used to express states in different period of time.Use of when is more general not specific. For the specific time, while is used.
Use of while
Unlike when, it is used for specific duration because there are two actions are happening at the same time.
Means the duration of one should be equal to the other.
•Both nations were negotiating while people agitating for the settlement.
•Children were enjoying outside while it was raining lightly.
•People are shouting against the firing while senior officials are appealing to calm down .
•His mother is preparing food while he getting ready for school.
All examples show fix duriation of time to express two actions.
While is preferred to use to express continuous tense. It is hardly used for simple tense.
The hidden meaning of ‘while’ is “during that time, whereas the meaning of “when” is at that time. Definite time limitation is essential to use while. But, it is not necessary for when.
The clear difference and explanation of both conjunctions of time are too confusing to grasp. But, I hope all these examples and clarification will prove helpful for you.