have + been + verb-ing

The perfectThe aspect expressing completion. E.g.: He’s finished university. continuousThe aspect expressing duration, formed with be + verb-ing. E.g.: What are you doing? is not considered as an aspectA verbal category relating an action to the passage of time. It can express duration or completion. in itself; rather it is the combination of the perfect and continuous aspects.

have + past participle 

Although in all of the following sentences we use going, each sentence refers to a different timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc.:

The gerund does not express any timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc. in itself, however it can show whether the actionA general term expressing that somebody or something does something expressed with it happened or happens earlier or not than something else in the sentence. We call this "something else" a time markerA verb or auxiliary that marks the reference point of a non-finite form. E.g.: The telephone is known to have been invented by Bell. ("is") He denied being in love with the suspect. ("denied") He must have arrived late. ("must").

Although in all of the following sentences we use go, each sentence refers to a different timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc.:

The aspect of a verbA part of speech that expresses an action or a state. E.g.: John seldom plays tennis. does not mark when an actionA general term expressing that somebody or something does something takes place in timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc., but shows the relationship between the action and the passage of time, seen from the speaker's point of view.

There are two aspects in English: the continuousThe aspect expressing duration, formed with be + verb-ing. E.g.: What are you doing? (also called progressAn action is in progress when it is happening. E.g.: When I arrived he was surfing. ("he was surfing")ive) aspect expresses durationA concept, related to the continuous aspect, expressing that an action is in progress. E.g.: What are you doing? ; the perfectThe aspect expressing completion. E.g.: He’s finished university. aspect expresses completionA concept, related to the perfect aspect, expressing that an action has finished. E.g.: He’s finished university..