Ответ:

Have they told to Ken about trip yet?

Yes, they have already told to him about trip

Has Pascal wrote to his Mum and Dad yet?

Yes, he has already wrote to his Mum and Dad

Has Grandad collected plane tickets yet?

No, he hasn’t collected them yet

Have they packed suitcases yet?

No, they haven’t packed them yet

Объяснение:

коротко объясню, потому что это прошедшее простое время