My keyboard adds a comma after every word.

Hello

One can suppose that every time you hit the spacebar, a comma is entered...

The problem may be "mechanical" in the sense that a "gadget" slipped between the keys causes both to function at the same time... Try cleaning the keyboard, blowing between the keys, using a brush...

It may also be "electrical" in the sense that a short circuit causes both keys to operate simultaneously... In this case, disassembly will be necessary... (not always easy to handle...)

See you soon

--
He who knows that he does not know knows more than he who does not know that he knows...

This is the original keyboard provided with my ACER. I don't see any specific reference on it. I'll try to change it for another one to see!
Thanks for the suggestions!

As you managed to solve your problem, because for me it makes points everywhere instead of a comma, thank you.

Yes, problem solved by… cleaning the keyboard! A crumb visible when lifting the keys.

What is the brand of your keyboard?
How long have you had your keyboard?
What is your operating system?

So I can't help you.