There's always a word to make the tense clear in the sentence, like "ontem" (yesterday) or "agora" (now). And we have no "present perfect", in Portuguese, but we have "past perfect", which means an action that started and finished in the past. We have no equivalent to the present perfect, but we can aproximate the meaning by using the construction: subject + verb TER + main verb in past participle OR subject + verb VIR + main verb in gerund
- Eu tenho andado sozinho
- Eu tenho cozinhado bastante
- Ela vem cuidando muito do cabelo
- Eu venho fazendo meus deveres de casa todos os dias.