Teori Present Perfect Tense

Present perfect tense is used to express action or situation that has or has occurred. When did the act or situation is not too important.

The formula for Present Perfect Tense:

SUBJECT + HAVE / HAS + Past Participle (V3)

(+) Positive: S + have / has + V3
(-) Negative: S + have / sas Not + V3
(?) Question: Have / has + S + V3

After the Subject (S) then use "have" or "has" suitable partner. Have in this context means: already, already, just now. The strange thing in english Have + Es but not Has. So like this:

He, She, It, John, Merry, Mufli: Has
You, We, They, Ellen and Budi: Have
 
Examples of the Present Perfect Tense:
(+) Positive: I have taken a bath.
(-) Negatives: I haven't taken a bath.
(?) Question: Have I taken a bath?

The characteristics of time that is usually used in the present perfect tense:
     - Already
     - For
     - Since
     - During
     - Not yet
     - Ever
     - Just
     - Lately
     - Recently
     - So far
     - Up to now
     - Until now