When did you come back?

When did you come back?
Lingling is in London with Sam and Amy.
Amy:Hello,John.How are you?
John:I'm fine,thank you.You're back from China!
Amy:Yes,we're home.
John:When did you come back?
Amy:We came back last Sunday.This is our Chinese friend,Lingling.
John:Hello,Lingling.
Lingling:Hi,John.Do you live in London,too?
John:Yes,I live near Amy and Sam.
Lingling:Amy,look at those ice creams!Let's buy some.
John:This is your ice cream,Lingling.
Lingling:Thank you!
Sam:We're going home now,John.Come with us.
Amy:There's our bus!Finish your ice cream,Lingling.
John:Hurry up,Lingling.Run!...Wait for us!
Lingling:Oh no!I dropped my ice cream!
John:Oh no!My new shoe!