Tuesday, February 17, 2009
Present perfect tenses are formed by putting "has" or "have" with the past participle of the verb (which usually ends in -ed).
Your sea monkeys have arrived. (occurred at some time in the past)
I have worked here for years. (is still going on)
The present perfect progressive tense describes an action that originated in the past, is still going on, and may keep going on in the future.
Present perfect progressive tenses are formed by putting "has been" or "have been" and the present participle of the verb (which usually ends in -ing).
I have been coughing up blood since 12:30 a.m.!