It's easy to confuse the simple past and present perfect tenses. And believe me, even native English speakers get these two mixed up.
So, what is the difference between the two?
Simple past tense: I fell out the window.
Present perfect tense: I have fallen out the window.
These two sentences seem to say the same thing, but they have one big difference: specificity.
The simple past tense sentence implies that you fell out the window at some point in the past, though the sentence doesn’t always have to mention when it happened.
To make it easier to check if it's a simple past tense, the sentence usually comes with an adverb that tells you when it happened.
I just fell out the window.
I fell out the window two days ago.
I fell out the window again this morning.
A sentence in the simple past tense is, as you may have guessed, simple. You have the subject, the verb in the past tense (as part of the predicate), and maybe an adverb of time in there somewhere.
I went to the hospital when I came to.
A doctor prescribed some medicine.
I took a cab home.
See? Simple enough to construct, even for a person who fell out the window.
To write a sentence in the present perfect tense, put in your subject, add in the word HAS or HAVE and the past participle of the verb you want to use, and the rest of the sentence.
I have been the subject of ridicule before.
My neighbor has always been up-to-date on the latest neighborhood news.
There have been times when I question my agility.
1. The simple past tense is for saying that something happened in the past, and you’re more or less sure of when.
2. The present perfect tense, on the other hand, is a little more vague about when something happened, because what only matters is that it did.
Now that you have learned the difference between the simple past and present perfect tenses, go and make up some sentences for practice. Don't throw these tenses out the window!