´do´ is de + o (of + the), so is used when you specify a definite (masculine) object, i.e Eu gosto do seu relógio (i like your (specific) watch). Only ´de´ is used for general things that you do not specify with a definite article i.e eu gosto de futebol (l like football (in general).
What's the purpose of ''do'' here? What's the difference between this sentence and ''eu gosto seu relogio?
From what I have read, the verb "gostar", is always followed by "de/do" in a sentence. http://www.semantica-portuguese.com/eu-gosto-de-voce-21059/?utm_source=Site+opt-ins_campaign=c94d7a5e68-AR_SEQUENCE_BEG_medium=email_term=0_957f563387-c94d7a5e68-96006261=0_957f563387-c94d7a5e68-96006261
Thanks reynj, i guess the sentence doesn't work without it. It probably wouldn't sound natural without it. One of deals where the person would know what you're saying but you wouldn't sound like a native. Obrigado novamente.
Is there any need of .. Do.. I learnt in perivious lessons that we always use de with gosto
so if i were to point out ...let say a watch on an Ad and i say i like it... would i use do?
yes, you would use 'do'. But you wouldn't use 'seu'- because you're not talking about a particular person's watch (seu= your/his/her). So it would be 'Eu gosto do relógio'.
Is there a clearer way to say I like your/his/her watch because seu is really ambiguous?
You could say: Eu gosto do relógio dele (his watch) or Eu gosto do relógio dela (her watch)- literally, the watch of him/her.
'Your watch' is limited to 'eu gosto do seu relógio', or in some regions of Brazil and I believe in Portugal 'eu gosto do teu relógio'- which only means <sub>your</sub> and cannot be confused with anything else.
Either of those is also correct. Since "seu" can apply to him, her, or you (você), you're correct that "eu gosto do seu relógio" could refer to any of the three. In that case, you'd pick up whose watch by the context of the conversation. If there's any ambiguity about whose watch you're talking about, you'd say "eu gosto do relógio dele/dela" or "eu gosto do teu relógio."