Ваш сын, должно быть занимается уже

Ваш сын, должно быть занимается уже пять часов подряд. Вам следует посоветовать ему погулять. У него может разболеться голова, если он будет продолжать работать без отдыха

Results (English) 1:

Your son must be engaged for five hours. You should advise him to walk. He can head ache if he will continue to work without rest

Results (English) 2:

Your son must have been practicing for five hours straight. You should advise him to take a walk. He may have a headache if he continues to work without rest.

Results (English) 3:

Your son must study for five hours in a row. You should tell him to go out. If he continues to work without rest, his head will explode.