The Difference: When vs. While (English Grammar) What’s the difference between the subordinate conjunctions when and while ? When & While: The Short Answer In some sentences, you can use either without a great change in meaning. Generally, if you want to focus on an action that has a duration being in progress , use a while + a progressive tense . While I was washing the dishes, my wife came home. * (Washing the dishes has a duration, e.g. 4 minutes.) (*Note you can also use when here, but as a general rule, while is suitable.) In other cases when you don’t need to emphasize that an action was in progress or the action is short and without a significant duration, use when and a simple tense . When it started to rain, we went inside. (The action started is short; it is not something in progress). Here are some tips on the use of these two conjunctions. ...