Although native English speakers use perfect verb tenses every day, they may not know it. If you are studying English grammar, these three tenses — present perfect, past perfect, and future perfect — may give you gray hair, even if you are only 12. And they have progressive forms, too!
Present perfect and present perfect progressive
The two present perfect forms show actions or states of being that began in the past but are still going on in the present. These forms are used whenever any action or state of being spans two past and present:
Roger and his friends have spent almost every penny of the inheritance. (have spent is in present perfect tense)
Lulu’s mortal enemy, Roger, has pleaded with her to become a professional tattooist. (has pleaded is in present perfect tense)
Now peruse these progressive examples:
Roger has been studying marble shooting for fifteen years without learning any worthwhile techniques. (has been studying is in the progressive form of the present perfect tense)
Lulu and her mentor Lola have been counting sheep all night. (have been counting is in the progressive form of the present perfect tense)
This mixture of present (has, have) and past is a clue to its use: present perfect tense ties the past to the present. When you use it, you're expressing an idea that includes an element of the past and an element of the present.
I have gone to the school cafeteria every day for six years, and I have not yet found one edible item.
This sentence means that at present I am still in school, still trying to find something to eat, and for the past six years I was in school also, trudging to the cafeteria each day, searching for a sandwich without mystery meat in it.
Past perfect and past perfect progressive
Briefly, each of these forms places an action in the past in relation to another action in the past. In other words, a timeline is set. The timeline begins some time ago and ends at some point before NOW. At least two events are on the timeline. Here are a couple of examples of the past perfect tense:
After she had sewn up the wound, the doctor realized that her watch was missing! (had sewn is in past perfect tense)
The watch had ticked for ten minutes before the nurse discovered its whereabouts. (had ticked is in past perfect tense)
Compare the preceding sentences with examples of the past perfect progressive (try saying that three times fast without spraying your listener!):
The patient had been considering a lawsuit but changed his mind. (had been considering is in the progressive form of the past perfect tense)
The doctor had been worrying about a pending lawsuit, but her patient dropped his case. (had been worrying is in the progressive form of the past perfect tense)
Future perfect and future perfect progressive
These two forms talk about events or states of being that have not happened yet in relation to another event even further in the future. In other words, these forms create another timeline, with at least two events or states of being on it.
First, take a look at the plain version of the future perfect:
Appleby will have eaten the entire piece of fruit by the time the bell rings at the end of recess. (will have eaten is in future perfect tense)
When Appleby finally arrives at grammar class, the teacher will have already outlined at least 504 grammar rules. (will have outlined is in future perfect tense)
Now take a look at the progressive form of the future perfect tense:
When the clocks strikes four, Appleby will have been chewing for 29 straight minutes without swallowing even one bite. (will have been chewing is in the progressive form of the future perfect tense.)
By the time he swallows, Appleby’s teacher will have been explaining the virtues of digestion to her class for a very long time. (will have been explaining is in the progressive form of the future perfect tense.)