Can you begin a sentence with "When"?

[jospan]

Hello,

I was wondering if you can begin a sentence with "When". I have not heard that it is grammatically incorrect to do so and am now in the final year of a Masters Degree. I have recently been told by an academic that I should never begin a sentence with When? Can anyone help us settle this query? Thanks, Jo

 

[Teia]

Hello,

I was wondering if you can begin a sentence with "When". I have not heard that it is grammatically incorrect to do so and am now in the final year of a Masters Degree. I have recently been told by an academic that I should never begin a sentence with When? Can anyone help us settle this query? Thanks, Jo

Of course you can start a sentence with when:

When are you going to leave on vacation?

When I arrive there, I`ll send you a postcard.

When the telephone rang, I was having a shower.

when - adverb:

at what time or period? how long ago? how soon?: When are they to arrive? When did the Roman Empire exist?

when - conjunction:

Whenever: When the wind blows, all the doors rattle.
During the time at which; while: When I was young, I was sick all the time.

when - Definitions from Dictionary.com