[Grammar] was home vs had been home

[davidtrinh]

I have written two sentences below.

(1) John and Mary were home when we were leaving for the airport.

(2) John and Mary had been home when we were leaving for the airport.

Yesterday, I talked about the sentences with my non-native English speaking friends. None of us could figure out how the two tenses simple past continuous and past perfect continuous changed the meaning of the sentences.

Please explain it. Thank you very much for your help.

 

[Tdol]

I don't see the reason for the past perfect in the second.

 

[Rover_KE]

The tenses in red are not past continuous; 'were leaving' is past continuous.