Verbs on a timeline revisited

For students who are intermediate or above, it is helpful to keep this timeline in mind.

Simple:

A specific moment. In the past the verb might be irregular. The 3ps in the present adds -s.

Something that happened, something that is true now, something that will happen.

verb-ed____________verb___________will verb
  ⇩_______________⇩_______________⇩

With the past: yesterday, last week, in 2017... Never, seldom, often...
With the present: always, sometimes, never, etc - see the post.


Continuous:

Over time. Past continuous uses was, were. Present uses am, are, is.

Something that was happening, something that is happening, something that will be happening.

was verb-ing______am verb-ing_____will be verb-ing
  ⇔________________⇔_______________⇔

With the past continuous: yesterday, last week, in 2017...
With the present continuous: today, at present, at the moment, right now, still...

Present perfect:

☊ have/has verb-ed
It is something that happened - or didn't happen - in the past that has an effect on the present or a connection to the present.

Something that happened before at an unstated time and that has an effect on the present.
May have just happened or happened a  long time ago.

Use with adverbs such as: ever, never, before, already, yet, just, for, since.

Have you ever seen a kangaroo?
I have never been to Korea.
I have eaten alligator before.
I have already talked to her about it.
She has not received her diploma yet.
They have just returned from their ski trip.
I have worked here for six months.
He has worked here since 1994.

The difficulty here for French speakers is What is the difference between the simple past and the present perfect? The answer is that for French speakers you used to use the passé composé for English Present Perfect and use passé simple for English Simple Past. However, now this is only true in literature, not in spoken French. Now French speakers use passé composé for both English Simple Past and English Present Perfect.

Wikipedia explains it well:

"Passé composé « Je suis arrivé. » ("I have arrived." I have come to town. I may have just arrived.)

and

Passé simple « J'arrivai. » ("I arrived." I came to town, but it is possible that I am not still here.)

The difference (regarding written language) is subtle. The passé simple is divorced from the present and has definitely been completed, while the passé composé is still connected to the present and may even still be happening."

This video does a good job of showing the difference.


Present Perfect Continuous:

☊ ⇔ have/has been verb-ing

With since and for.

I have been working since this morning.
My girlfriend has been studying there since 2015.
It has been raining since yesterday.
He has been preparing to take his driver's test for six months.
They have been waiting for 2 hours.