Romanian is very liberal with using a subject in sentences.
'Eu sunt un baiat.' Or 'Sunt un baiat.'
Mean broadly the same thing and can be used interchangeably. Unless you really want to emphasise that it is you who is a boy then you would say 'Eu sunt un baiat' <I am a boy>
This works the same for Spanish and Portuguese. Makes it easy for me since they're Romance languages.