Chapter 5 : Present Perfect Tense

Present Perfect  Active & Passive Voice

Active Voice  S + V to have (have, has) + V3 He has written a letter to his friend for 3 hours.  Passive Voice S + V to have + been + V3 A letter has been written (by him) for 3 hours.

Present Perfect Negative Form Active & Passive Voice

Active Voice  S + V to have (have, has) + not + V3 He hasn't written a letter to his friend for 3 hours.  Passive Voice S + V to have + not + been + V3 A letter hasn't been written (by him) for 3 hours.

Present Perfect Question Form Active & Passive Voice

Active Voice  V to have (have, has) + S +  V3? Has he written a letter to his friend for 3 hours.? Passive Voice V to have + been + S + V3? Has a letter has been written (by him) for 3 hours?

Present Perfect Usage
Present Perfect is used in the following situations:

1. Uncompleted Action/Tasks.
   In this situation, present perfect is used to describe an action that started in the past and are not finished.
   Example:
   I have studied for more than 3 hours. (I am still studying)
   She has cried since 3 o'clock for her lost dog. (she is still crying)
   We have not finished preparing our food. (we're still preparing our food)
   
2. Completed Action/Tasks.
   In this situation, present perfect is used to describe an action that started in the past and continued for some time but it has already been finished before the present.
   Example:
   I have already done my job, now it is your turn. (I no longer need to do that job, I did my job)
   She has stop crying for one hour. (she is still crying)
   We have finished preparing our food. (we're done with the food preparation)
   
3. An Experience.
   For this situation, present perfect is used to talk about an action that happened in the past and has already stopped
   Example:
   He has had a car accident this morning.
   This is the first time I have ever eaten a snake.
   Have you ever been to England?
   I have never met him before.
   John has been in New Zealand in the last year.

Present Perfect Tense Keyword:

Keyword	คำแปล
already	แล้ว
just	พึ่งจะ
yet	ยังไม่
ever	เคย
never	ไม่เคย
for	เป็นเวลา
since	ตั้งแต่
so far	ขณะนี้
up to now	จนถึงขณะนี้
not yet	ยังไม่
lately	เมื่อเร็วๆนี้
recently	เมื่อเร็วๆนี้
in the last year/month	ในช่วงปี/เดือนที่แล้ว

Past Continuous Keyword Usage

Since VS For
Since used to refer to the point of time that action has happened. While for refers to a period/length of time that action has happened.
I have been here since this morning.
I have been here for 3 hours.

Have Gone VS Have Been
have/has gone refers to an action that someone has gone to a place and he/she has not returned yet. While have/has been refers to an experience i.e. a place that someone has visited sometime in his/her life.
I am sorry she has gone to Paris. I am not sure when she will return.
I have been in Australia for 4 years (I used to live in Australia). Now, I am living in Bangkok.
She has been to most of the European capitals (I used to visited most of the European capitals).

Never
Never use "not" with the sentence that has "never".
My friend has never been to Thailand.
My friend hasn't never been to Thailand. X

Present Perfect Tense - Videos Section

[:- Present Perfect Tense -:] [:- Present Perfect Tense - Uncompleted Actions -:] [:- Present Perfect Tense - For VS Since -:]

Reference: englishpage.com