On the other hand, the past perfect continuous is used to express a continued or ongoing action that started in the past and continued sometime in the past. The action began in the past, continued in the past and (usually) ended in the past e.g. “She had been doing her homework since lunchtime, and now needed a break” Present Perfect Continuous. This form is used to refer to something that began in the past but is still happening at the time of speaking. Example: I have been reading Gulliver’s Travels for the last week. Words often used with the Present Perfect Continuous Tense: Since/for. Since: suggests the ‘point of time’ Past Perfect Continuous Tense. This tense is used to express an action that started in past and continued for some time in past. It states the continued nature of an action which started at some point in past, continued for some (more or less specific) time in past. Therefore, a time-reference is given in the sentence to show when the action Past continuous implies the waiting is now finished: We were waiting since noon. The present perfect could suggest the waiting has only recently finished or even that it is still ongoing: We have waited since noon. The present perfect continuous suggests the action is still ongoing and emphasizes the length of it: We have been waiting since noon .

present perfect continuous tense since for