Bihar Police Constable Model Paper 2

• 'While' means during the time that, or at the same time as.
• 'When' means at what time; at the time at which.
• 'Whereas' means compared with the fact that; but
• 'Until' means up to (the time that).
• Now, when we have two continuous actions happening at the same, then we usually use while.
• Example: Right now, I’m recording a video while my husband is working.
• Now, when we have two single actions that happen at the same time or one happens right after another one, then we tend to use when.
• Example: I picked up the phone when it rang. (First, the phone rang, and then immediately I picked up the phone.)
• Since only after landing the person will ring another person, 'when' is more suitable to use here.

Thus, the complete sentence is: When I land at the airport, I will ring you up.