Dlaczego w pierwszym zadniu jest they are, a w drugim samo they?

'Apart from that, in many cases they are paid very little money for their work.'

'As a result, some of them may get discouraged from work altogether because they see that it does not make much sense.'

Dlaczego w pierwszym zadniu jest they are, a w drugim samo they? Jaka jest reguła?

Passive vs. active.

nie moze byc modalne 'may' wyrażone w formie continuous