"depuis" means "since" or "for" and is what you use to express a continuous action, one that started in the past and is still going. Always use "depuis" with the present conjugation of the verb in French, hence "je l'attends"
Thank you for quickly answers,both you.So it means to say that the "depuis" is quite necessary,so I got it.And"I have been living in a prison of fear since that day."==="je vis dans une prison de peur depuis ce jour-là."
Am I right?
"I have been waiting here for hours": Ça fait des heures que j'attends ici
"I have waited here for hours": J'ai attendu ici pendant des heures
"I waited here for hours": J'ai attendu ici... or J'avais attendu ici...
"I was waiting here for hours: J'ai attendu ici... or J'avais attendu ici...
Sometimes the imparfait is indeed the equivalent of the progressive tenses in English, but not really in this particular case. One could say "J'attendais ici..." to express a concomitent event e.g. "J'attendais ici lorsque je l'ai vu passer".
When we use "for" and "since" in English with a present perfect (+ing) to indicate that we started something in the past and it still continues:
I've been waiting here for hours. / I've known my best friend since 2002.
in French, they disregard the notion of past and retain the idea that the action still continues now and they use a present tense:
J'attends ici depuis des heures. / Je connais mon meilleur ami depuis 2002.