ref –

• https://www.englishclub.com/grammar/verb-tenses_present-perfect.php
• https://www.espressoenglish.net/difference-between-present-perfect-and-past-perfect-in-english/
• https://www.natterandramble.co.uk/present-perfect-tense-timeline-form-uses/

Perfect in latin means ‘action that has been completed’.

Present Perfect is an action that started in the past and continues to the present:

I have lived in this city for six months.

An action that happened before now (unspecified time) and is complete:
I have been to Japan twice.

With Present Perfect, one thing happened before the other, but one thing happened in the past, the other happened in the present.

Whereas in Past Perfect, one thing happened before the other, and they BOTH happened in the past.

Subject + [have/has] + past participle

Present Perfect tense

There is always a connection with the past and with the present.

The present perfect tense is used to show an action that happened in the past that is directly related to the present, such as actions that are still continuing or that indicate a change over time.

Six situations to use Present (Perfect)

1 – Habit: An ongoing action that started in the past, and is repeated up to the present

examples

The professor has [taught] here for two decades.

I (First person singular) have [been] here for twenty minutes.

They (Third person plural) haven’t (have not) [lived] here for years.

John (third person singular) hasn’t (has not) [called] for six months.

She (third person singular) has [worked] in the bank for five years.

We (First person plural) have [had] the same car for ten years.

He (third person singular) has [worked] in New York for a long time.

If you want to use ‘since’, the common trait is that the time between the past and now tends to be months or years. But sometimes, we can use hours too:

• I (First person singular) have [been] here since 9 o’clock.
• Have you (Second person singular) [played] the piano since you were a child?
• He has lived here since 1993.
• You have worked here since you left school.
• He (third person singular) has [worked] in New York since he left school.
• John (third person singular) hasn’t (has not) [called] since February.
• They have been at the hotel since last week.
• I haven’t ridden a horse since I was 9.
• I haven’t been on holiday since last year.
• They have [played] piano since the age of three.
• I have [worked] here since June.

2 – Experiences

The present perfect tense emphasizes the effects or consequences of the action.

I have [seen] an alien.

He has [lived] in Bangkok.

Have you [been] there?

We have never [eaten] caviar.

3 – An action that was completed very recently, so recent that it’s directly connected to the present

If an action was only completed very recently, you can describe it with the present perfect tense.

Even though the action happened in the past, it was so recent that it’s directly connected to the present. These cases usually use adverbs like just or now to show that the action “just now”.

I should not eat anymore because I have [just brushed my teeth]

We have [finished practice now], so let’s go home.

4 – A change over time

The present perfect tense is often used to emphasize a change that happened over an extended period of time.

My cousin has [grown so much] since I saw her two years ago.

Thanks to the many months of playing, I have [become an expert] at Wordle.

I have [bought a car].

John has [broken his leg].

Has [the price gone up]

The police have [arrested the killer]

5 – An uncompleted action that is expected to be finished (in the negative)

If an action started in the past but was not completed, you can describe it with the present perfect tense if it’s likely to be completed in the future. This situation uses the negative form to show that the action is still unfinished and often uses the adverb yet.

The jury has [not reached a verdict (yet)].

I have [not finished my paper], but it’s due in an hour!

6 – To add significance to a completed action

You can use the present perfect tense to make any past action sound more important. The present perfect tense is often used with great achievements or accomplishments, as well as dramatic or rare events. This makes it appropriate for newsworthy events or major life experiences.

Macbeth has [killed the king]. (king now dead)

I have [met the love of my life]! (still with that person)

Additional Notes

have – First, second, and third plural
has – third person singular
resent (and will probably continue into the future). This is a situation (not an action). We usually use for or since with this structure.

First, Second, third person plural have.
Third person use has.

Note on usage of have/has vs had:
As a main verb, use have/has for the present tense and had for the past tense.

ref – https://www.grammarly.com/blog/irregular-verbs/

Irregular verbs are verbs that do not follow the normal patterns for tense and past participle. While most English regular verbs use the ending “-ed” for the past tense and participle forms, irregular verbs each have their own unique tense forms and past participles.

Irregular verbs are one of the hardest parts of the modern English language because they’re all a little different. Since there’s no formula, English speakers have no choice but to memorize each one, along with their special verb forms.

What are irregular verbs?

You could say irregular verbs are verbs that “follow their own rules.” Regular verbs follow the standard grammar rules of modern English in adding “-ed” or “-d” to form the past tense and past participle forms. Irregular verbs, however, use completely original words for their different verb forms when they’re the main verb of a sentence. (Just a reminder: The past participle is the form used with the present perfect tense.)

To show you what we mean, let’s “dance” and “sing!” This pair is a good example to see the differences:

“dance” is a regular verb,
but “sing” is an irregular verb.

To conjugate “dance,” there’s no big surprise or trick; you just use the same formula as with most other verbs. To create both the simple past tense and past participle forms, you simply add “-ed,” or in this case only “-d” because the base form ends in e already.

Base – dance
Simple Past Tense – danced
Past Participle – danced

“Sing,” however, is irregular, so the normal rules don’t work. You can’t use “singed” because that’s an incorrect form for this verb.

Instead, “sing” has both a unique past tense and also a unique past participle form. The only way to know how to conjugate “sing” is to memorize its special forms.

Base Simple – sing
Past Tense – sang
Past Participle – sung

In practice, you end with conjugations like these:

We sang and danced all night.

I have sung opera before, but I have never danced to it.

She prefers music sung by professionals.

The simple present tense is conjugated the same no matter whether the verb is regular or irregular. This includes adding an “-s” or “-es” for the third-person singular. Be aware that certain exceptions, like the verb “be,” have special present tense forms as well.

Base Present Tense Simple Past Participle Past Participle
be am, is, are was, were been
Like “be,” quite a few other linking verbs are irregular as well, such as “become” and “feel.” Also, irregular verbs can be either transitive or intransitive verbs and can still be used as imperative verbs.

Strong vs. weak verbs
Irregular verbs and regular verbs are often confused with strong verbs and weak verbs, although they are very similar.

Strong verbs are any verb that changes its vowels in the past tense, like how the i in “sing” changes to an a for the past tense.

Weak verbs, on the other hand, keep their vowel the same in the past tense, like the a in dance.

With these rules in mind, we can see that all strong verbs are irregular. The confusion comes with weak verbs, because some weak verbs are irregular, too. One of the most common examples of an irregular weak verb is “sleep”:

Base Simple Past Tense Past Participle
sleep slept slept
Although “sleep” has its own special past tense and past participle forms (“slept”), it still keeps e as the main vowel, making it a weak verb.

Likewise, irregular verbs that don’t change at all, like “bet” or “spread,” are also weak. You can find a full list of irregular verbs that don’t change below.

List of irregular verbs in English

Want a list of irregular verbs in the English language? Below we list the common irregular verbs to help you study and provide a quick-reference resource in case you forget one later (note that the past tense verbs in the chart below are shown in American English forms; there are some differences in British English).

Instead of listing the irregular verbs in each of their verb tenses, we only mention the simple past tense and past participle forms, along with the base. Any verb conjugation you do will use one of those three forms.

Please note irregular verbs that take a prefix (e.g., “resell” or “undo”) use the same irregular forms as their base word (e.g., “resold” or “undid”).

Also, you’ll notice that some irregular verbs don’t change at all—the base, simple past tense, and past participle forms are all the same word. We discuss this type of irregular verb in the next section.

Base	Simple Past Tense	Past Participle
arise	arose	arisen
awake	awoke	awoken
be	was/were	been
bear	bore	borne
beat	beat	beaten
become	became	become
begin	began	begun
bend	bent	bent
bet	bet	bet
bind	bound	bound
bid	bid	bid
bite	bite	bitten

bleed bled bled
blow blew blown
break broke broken
breed bred bred
bring brought brought
broadcast broadcast broadcast
build built built
burst burst burst
buy bought bought
cast cast cast
catch caught caught
choose chose chosen
cling clung clung
come came come
cost cost cost
creep crept crept
cut cut cut
deal dealt dealt
dig dug dug
dive dove/dived dived
do did done
draw drew drawn
dream dreamed (sometimes “dreamt”) dreamed (sometimes “dreamt”)
drink drank drunk
drive drove driven
eat ate eaten
fall fell fallen
feed fed fed
feel felt felt
fight fought fought
find found found
flee fled fled
fling flung flung
fly flew flown
forbid forbade forbidden
forget forgot forgotten
forgive forgave forgiven
freeze froze frozen
get got got
give gave given
go went gone
grind ground ground
grow grew grown
hang hung (sometimes “hanged”) hung (sometimes “hanged”)
have had had
hear heard heard
hide hid hidden
hit hit hit
hold held held
hurt hurt hurt
keep kept kept
kneel knelt knelt
know knew known
lay laid laid
lead led led
leave left left
lend lent lent
let let let
lie (as in “lie down”) lay lain
light lit/lighted lit/lighted
lose lost lost
make made made
mean meant meant
meet met met
mistake mistook mistaken
mow mowed mown/mowed
overtake overtook overtaken
pay paid paid
proofread proofread proofread
put put put
quit quit quit
read read read
reset reset reset
ride rode ridden
ring rang rung
rise rose risen
run ran run
say said said
see saw seen
seek sought sought
sell sold sold
send sent sent
set set set
sew sewed sewn/sewed
shake shook shaken
shave shaved shaven
shed shed shed
shine shone shone
shoot shot shot
show showed shown
shrink shrank shrunk
shut shut shut
sing sang sung
sink sank sunk
sit sat sat
slay slew slain
sleep slept slept
slide slid slid
sling slung slung
sneak snuck (sometimes “sneaked“) snuck (sometimes “sneaked”)
sow sowed sown/sowed
speak spoke spoken
speed sped sped
spend spent spent
spill spilt/spilled spilt/spilled
spin spun spun
spit spat spat
split split split
spread spread spread
spring sprang sprung
stand stood stood
steal stole stolen
stick stuck stuck
sting stung stung
stink stank stunk
strike struck struck
string strung strung
strive strove striven
swear swore sworn
sweep swept swept
swell swelled swollen/swelled
swim swam swum
swing swung swung
take took taken
teach taught taught
tear tore torn
think thought thought
throw threw thrown
thrust thrust thrust
tread trod trodden
understand understood understood
upset upset upset
wake woke woken
wear wore worn
weave wove worn
weave wove woven
weep wept wept
wet wet/wetted wet/wetted
win won won
wind wound wound
wring wrung wrung
write wrote written

Common irregular verbs that don’t change

Most verbs, both regular and irregular, have different verb forms for different tenses. We add letters or change the spelling to aid communication; it helps the listener or reader understand whether you’re talking about the present, past, or future.

However, certain verbs don’t change verb forms at all. They use the same word and same spelling for the present, past, and past participle forms. Because these words don’t follow the normal rules, they’re also considered irregular.

You can find these words in the chart above, but to speed up your search we’ve also included them in the list below:

bet
bid
broadcast
burst
cast
cost
cut
hit
hurt
let
proofread (see “read”)
put
read (past and past participle are spelled the same but pronounced differently)
reset
set
shed
shut
split
spread
thrust
upset
wet

ref –

• https://www.grammarly.com/blog/past-continuous-tense/
• https://www.natterandramble.co.uk/past-continuous-timeline-form-uses/

Subj + [was/were] + verb+’ing’

The past continuous tense shows a continuous action that began in the past.

The Past:

5 past continuous tense uses and examples

1) An action in the past that gets interrupted

One of the most common uses of the past continuous tense shows a past action that was interrupted by another past action. These are often complex sentences featuring subordinating conjunctions like when, while, before, after, until, or whenever.

Put the action that was interrupted in the past continuous tense and the action that interrupts it in the simple past.

• [Marta was leaving her apartment] ( <-- past continuous) when [she heard the thunderstorm] ( <-- simple past).
• [They were sleeping peacefully] ( <-- past continuous) until [the alarm rang] ( <-- simple past)
• [My parents arrived] ( <-- simple past) while I was shopping ( <-- past continuous).

2) Ongoing actions at a specified time in the past.

When you mention an exact time in the past, use the past continuous tense if the action started before that time and continued afterward. If the action begins at the time mentioned, use the simple past instead.

• At midnight (exact time in past), everyone at the party was still having fun (action started before, past continuous).
• I was working as a cashier (action started before, past continuous) in October (exact time in past).
• By the age of nine (exact time in past), I was training to be a ninja (action started before, past continuous).

3) Habitual actions in the past (usually with adverbs like always)

Use the past continuous tense to talk about an action that used to be done frequently in the past but is not done in the present.

This form is usually used with adverbs and adverb phrases, specifically ones that suggest the action was done a lot, like those listed below:

As a baby (but not anymore), my brother was always making a mess (action done frequently in the past, past continuous).

My first year of college (but not anymore), I was making spelling mistakes all the time (action done frequently in the past, past continuous).

She was forever (but not anymore) trying to impress her crush (action done frequently in the past, past continuous).

4) Emphasizing how long a past action took

This form usually uses adverb phrases (describes an action) that explain the length of time, such as:

all morning/afternoon/evening
all day/night
all week/month/ year
for hours/days/weeks/months/years
the whole time

The players were training (action/verb) all year for this match.

She was gardening (action/verb) all morning and missed the delivery.

I was trying to complete (action/verb) the final level for hours.

5) Setting the background for a story

When telling a story (or writing one), you can use the past continuous tense to “set the scene,” or describe exactly what was happening at the beginning of your story. We use the past continuous tense because these actions were, presumably, already happening before the story began.

Past continuous tense examples:

The birds were singing (past continuous), and the sun was shining (past continuous). I knew it would be a good day.

Everyone at the cafe was enjoying their coffee (past continuous). Then the stranger appeared.

The city was going about its business (past continuous) without knowing the aliens had arrived.

Past continuous vs Simple Past

“My hamster was sleeping all day” and “My hamster slept all day” have the same meaning.

The simple past is generally more commonly used. However, there are subtle differences worth mentioning in certain situations.

The past continuous tense means the action started before the other action.
The simple past means one action started after the other.

In the example below, which uses the past continuous, the speaker started running before the whistle blew:

When the whistle blew, I was running.

PAST [—— was running —— (whistle blew) — running –]—— NOW ——— FUTURE

In this example using the simple past tense, the speaker started running after the whistle blew:

When the whistle blew, I ran.

PAST [— (whistle blew) — ran —— — running –]—— NOW ——— FUTURE

Likewise, when you mention a time directly, the past continuous tense means the action started before the time, whereas the simple past means the action started at the time. Here, the speaker started eating lunch before noon:

At noon I was eating lunch.

PAST [—— was eating lunch —— (at noon) — eating lunch –]—— NOW ——— FUTURE

Here, the speaker started eating lunch at noon:

At noon I ate lunch.

PAST [— (at noon) — ate lunch —— — running –]—— NOW ——— FUTURE