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?”
  • 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?”
  • 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