Use Present Perfect. He____to a new song.(just,listen)
I can't write the dictation! I__the rule(not yet,learn)
The children__that computer game.(already,play)
My cousin__his book.(not find).
I can't find sweets! Who __ all the sweets?(ear)
Mike__ his homework and now is playing in the yard.(already,do)

Has just listened

Have not learned yet

Have already played

Has not found

Have eaten

Has already done