The Word is:”when”
when
/wɛn/
adverb
adverb: when
1. at what time.
“when did you last see him?”
how soon.
“when can I see you?”
in what circumstances.
“when would such a rule be justifiable?”
“when can I see you?”
“when would such a rule be justifiable?”
adverb
adverb: when
1. at or on which (referring to a time or circumstance).
“Saturday is the day when I get my hair done”
conjunction
conjunction: when
1.at or during the time that.
“I loved maths when I was at school”
after.
“call me when you’ve finished”
at any time that; whenever.
“can you spare five minutes when it’s convenient?”
“call me when you’ve finished”
“can you spare five minutes when it’s convenient?”
2. after which; and just then (implying suddenness).
“he had just drifted off to sleep when the phone rang”
3. in view of the fact that; considering that.
“why bother to paint it when you can photograph it with the same effect?”
4. although; whereas.
“I’m saying it now when I should have told you long ago”
Source credit: Google