Hello, everyone!

Which sentence is correct and why?
Are they both correct?

1- The last year has been a learning curve for me.
2- The last year was a learning curve for me.

I'm puzzled by the use of "The last year" + present perfect.
Here's another example from Twitter. The president Biden on Twitter said:
"The last year has been a year of challenges, but it's also been a year of enormous progress."

Thank you in advance!

Question

Hello, everyone!

Which sentence is correct and why?
 Are they both correct?

1- The last year has been a learning curve for me.
2- The last year was a learning curve for me.

I'm puzzled by the use of "The last year"  + present perfect.
Here's another example from Twitter. The president Biden on Twitter said:
"The last year has been a year of challenges, but it's also been a year of enormous progress."

Thank you in advance!

Answer

Hi Raquel,

In the first sentence we can see the present perfect tense being used to describe an activity which started in the past, with continuing results in the present, or is perhaps continuing still. 
The subject here is ‘the past year’. The learning curve is not over, nor is it completely separated from the present moment. 
Another: ‘This morning has been very busy!’ 
This started in the past and is not over, it’s continuing still.

The second sentence is past simple. The feeling here is that whatever happened before is now over. There is not so much a connection to the present moment.

So both are correct, with different emphasis. 
I hope that helps, let me know if you have any questions.