1. Perfect Tenses

2. Present Perfect Unfinished Actions
1: We use this tense when we want to talk about unfinished actions or states or habits that started in the past and continue to the present. Usually we use it to say 'how long' and we need 'since' or 'for'. We often use stative verbs.
I've known Karen since 1994.
She's lived in London for three years.
2: Life experience. These are actions or events that happened sometime during a person's life. We don't say when the experience happened, and the person needs to be alive now. We often use the words 'ever' and 'never' here.
I have been to Tokyo.
They have visited Paris three times.

3. 3: With an unfinished time word (this month, this week, today)
3: With an unfinished time word (this month, this week, today). The period of time is still continuing.
She's drunk three cups of coffee today.
I've already moved house twice this year!
!! We CAN'T use the present perfect with a finished time word. NOT:I've seen him yesterday.
4: A finished action with a result in the present (focus on result). We often use the present perfect to talk about something that happened in the recent past, but that is still true or important now.
She's hurt her leg (so she can't play tennis today).
They've missed the bus (so they will be late).
5: We can also use the present perfect to talk about something that happened recently, even if there isn't a clear result in the present. This is common when we want to introduce news and we often use the words 'just / yet / already / recently'.
I've just seen Lucy.
The Mayor has announced a new plan for the railways.

4. Simple or Continuous? Simple Continuous Both Ongoing situations
With state verbs such as know, understand or like to talk about an unfinished action.
I’ve known him since April.
To emphasise that an action has continued for a long time or is repeated. Often with verbs of duration: wait, stay, run, play, sit, stand, etc.
I’ve been waiting for you for more than two hours.
I’ve been standing in the queue the whole morning.
We can use both present perfect simple or continuous to talk about situations that started in the past and continue into the present. Particularly with verbs like do, work, study or live, there’s no difference in meaning.
I’ve worked in the company for 3 years.
I’ve been working in the company for 3 years.
Completed actions (recent or in time up to now)
For actions that are short and complete (drop, cut, break, stop, lose, etc…
I’ve broken my arm.
She’s dropped the glass.
To emphasize a completed action or a result. It often answers the questions: How many? How much? How far?
He’s called me ten times today.
They’ve run 10 kilometres so far.
Present evidence
When there is a present evidence of a recent longer activity.
The floor is wet. It’s been raining for 3 hours.
A: It smells funnny.
B: Oh, sorry, I’ve been cooking sardines.

5. Past Perfect 1: A finished action before a second point in the past.
When we arrived, the film had started (= first the film started, then we arrived).
!! We usually use the past perfect to make it clear which action happened first. Maybe we are already talking about something in the past and we want to mention something else that is further back in time
It had snowed in the night, so the bus didn't arrive.
If it's clear which action happened first (if we use the words 'before' or 'after', for example), the past perfect is optional. The film started before we arrived / the film had started before we arrived.
2: Something that started in the past and continued up to another action or time in the past. The past perfect tells us 'how long', just like the present perfect, but this time the action continues up to a point in the past rather than the present. Usually we use 'for + time'. We can also use the past perfect continuous here, so we most often use the past perfect simple with stative verbs.
When he graduated, he had been in London for six years. (= He arrived in London six years before he graduated and lived there until he graduated, or even longer.)
On the 20th of July, I'd worked here for three months.

6. Past Perfect Continuous  focus on the process
3: To talk about unreal or imaginary things in the past. In the same way that we use the past simple to talk about unreal or imaginary things in the present, we use the past perfect (one step back in time) to talk about unreal things in the past. This is common in the third conditional and after 'wish'.
If I had known you were ill, I would have visited you.
She would have passed the exam if she had studied harder.
I wish I hadn't gone to bed so late!
Past Perfect Continuous  focus on the process

7. Participle Clauses
Perfect participle clauses: If we want to make it clear that an action happens before another one, we use a perfect participle for the earlier action
Having washed the car, I noticed a small scratch on the front right fender. (After I washed the car, I noticed a small scratch on the front right fender.). Here the present participle (washing the car) would mean "while I was washing the car".
!!! If the two actions do not follow each other immediately or if the first action happens over a period of time, we use a perfect participle instead of a present participle for the earlier action:
Having seen the film before, I didn't want to go to the cinema. Mark knew the town well, having lived there all his life.
Past participle clauses: replace passive voice finite clauses
Shocked by the explosion, the people ran for shelter. (The people were shocked by the explosion and ran for shelter.)
The musicians stood up, surrounded by thunderous applause. (The musicians stood up while they were surrounded by thunderous applause.)
!!! If we want to emphasise that an action happens before another one, we use a passive perfect participle:
Having been nominated three times for an Oscar, he is one of today's most acclaimed film directors.

8. PREVIOUS NOTES ON PARTICIPLE CLAUSES OR REDUCED RELATIVE CLAUSES
1. A present participle (verb + ing) can be used in the same way as an active relative clause:
The man driving the car is a friend of mine. = The man who is driving the car …
Lorries coming over the bridge have to be careful of the wind. = Lorries that come over…
Who was the girl wearing the red dress? = Who was the girl who was wearing the red dress?
2. A past participle can be used in the same way as a simple passive relative clause:
We read the sent by the manager. = We read the that had been sent …
This vase, made in China, is very valuable. = This vase, which was made in China, …
3. 'Being + past participle' can be used in the same way as a continuous passive relative clause:
The poem being read by the actor was written by my brother. = The poem that is being read by…
The cakes being eaten at the wedding were made here. = The cakes that are being eaten…

9. Infinitive Forms Compare: I seem to have lost my wallet.
He seems to lose control all the time.
He is believed to kill animals.
He is believed to have killed a person.

10. Future Perfect Future perfect simple Future perfect continuous
- Something that will be finished by or before an specific time in the future: Fran will have uploaded the photos by now.
- The length of time that an action will have lasted for at a point of time in the future: I will have had this phone for a month on Thursday.
!!! We can use WILL/ WILL HAVE to refer to the present to talk about what we believe:
Many people WILL HAVE VISITED the city just to see it.
Where are you from? / You won’t have heard of it. It’s tiny.
Future perfect continuous
- Showing that something will continue until a particular event or time in the future: The boys will have been playing this game for a year when the the new version comes out.
- Actions that will be in progress in the future and will have an effect on a later action: Soo she won’t type at all because she will have been using the voice to text app for months.

11. Other Modals
Instead of will, you can also use other modal verbs such as MAY or SHOULD.
Other cities may have failed because they didn’t take up the other strands of Bilbao’s regeneration project.
I should have finished my work by six, but I’ll call you if I haven’t.
PAST MODALS:Could have, should have, would have