有關現在完成式問題問一問

The Present Perfect Tense:-
The Present Perfect Tense ,took place in past, is associated with the present idea of now,eg:-
I have repaired cars. (Up to Now)
I have repaired all the cars in this circumstance. (So now I am fully informed)
The Present Perfect Tense is used:-
(1)For an action just concluded when the resulting state is still present, eg:-
I have repaired my cars; I am able to drive.
The car has just repaired; there is nothing to prevent me from driving with a licence.
With activities completed in the immediated past, just is often used, eg:-
The car has just repaired.
Note that though "just" is an adverb of the present tense,
"just now" =a little time ago" is an adverb of the past
and the verb used with it will be a Past Tense, eg:-
The car repaired just now.=(just now)
(2)For duration of an action or of absence of an action which had begun in the past and continuing to the present,and possibly to the future,eg:-
I have repaired cars for (11-09=2 hrs)
I have repaired cars (a car mechanic) for 2 hrs.(and am still saying about it in 11:00:01-11:00:00=00:01 sec.)
Compare this with:-
I repaired this car for 2 years (but no longer repair it.)

2014-03-23 11:39:25 補充：
(3)I have ironed my clothes for(2-1=1 hrs).
Or since 15:00:01-15:00:00=00:01 sec ago=just 1 sec.ago.

2014-03-23 15:03:12 補充：
(4)So's grammar is the way he does not obey the Rules of Grammar when he writes or speaks ,reads or listens...... a deterioration in spelling and English Grammar among teenagers HK.
If you ignore someone,
the Ed.ignored English Grammar advice to drop the possessive case in Grammar to them already.

呢位朋友的強逼性心理障礙真係好嚴重，各位大大可否不再回答此類問題，否則等如鼓勵這位朋友繼續不停發問，越踩越深。當然不回答亦不能幫到甚麼，不同意的請ignore我的意見。