The use of while in English is often confused with when, as both have the meaning of “during the time that”. So what is the correct usage of the word while?
While can be used as a noun and a conjunction. As a noun, it can be translated as a period of time or a moment. As a conjunction, while can mean “during the time that” or “at the same time as”. It can introduce a time adverbial clause or a concessive clause. When while connects two parallel sentences, it indicates a contrasting relationship.
When while is used to introduce a time adverbial clause, it can be placed at the beginning or end of the sentence. However, when while is used to introduce a concessive clause, it is generally placed at the beginning of the sentence and not at the end. In a concessive clause introduced by while, if the subject of the clause is the same as the subject of the main clause, both the subject and the verb “be” in the clause can be omitted.
