Both tenses talk about the past, but they look at it differently. The past simple is for a finished time you could point to on a calendar. The present perfect connects the past to right now: your life experience so far, or a situation that is still going on.
The pattern
I moved to Dallas in 2019.
I have lived in Dallas for five years.
01Finished time: use the past simple
When you name a finished time, or the listener clearly knows it, use the past simple. Words like yesterday, last week, in 2019, two hours ago and when I was in college close the door on the action. It's over.
Questions with When...? and What time...? also ask about a finished moment, so they take the past simple too.
- We drove to Austin last weekend.
- She started her new job two weeks ago.
- When did you get your green card?
02Life experience: use the present perfect
To talk about something that happened at some point in your life, with no specific time, use have/has + past participle. Ever and never are very common here.
Once you start giving details (when, where, who with), switch to the past simple, because now you are talking about one finished event.
- Have you ever been to Chicago?
- Yes, I have. I went there for a conference last spring.
- I've never tried grits.
03Unfinished time: for and since
If a situation started in the past and is still true now, use the present perfect with for (a length of time) or since (a starting point). The present simple is wrong here: say "I've lived here since 2020," not "I live here since 2020."
| for + length of time | since + starting point |
|---|---|
| for three months | since March |
| for ten years | since 2016 |
| for a long time | since I was in high school |
04Just, already and yet in American English
In the US, the past simple is completely normal with just, already and yet, especially in conversation. The present perfect is also correct. British textbooks often teach only the present perfect here, but both forms are standard American English.
| Very common in the US | Also correct |
|---|---|
| I just ate. | I've just eaten. |
| Did you call him yet? | Have you called him yet? |
| She already left. | She's already left. |
05Common mistakes
I have visited my aunt in Seattle last month.
I visited my aunt in Seattle last month.
Last month is a finished time, so use the past simple.
I live here since 2020.
I've lived here since 2020.
A situation that started in the past and continues now needs the present perfect.
How long are you in the US?
How long have you been in the US?
You are asking about a period from the past up to now.
Have you ever went to Miami?
Have you ever been to Miami?
After have, use the past participle, not the past simple form.