I want to know whether it is really important to learn grammar in order to learn any language specially English. If there is no any other way?

Grammar is important when learning any language, even computer programmers have to learn the correct grammar and syntax.

Grammar is important because there is a difference between...

Do you want to eat Grandma?

Or...

Do you want to eat, Grandma?

In one, you want to eat your grandmother, in the other, you are asking your grandmother if she wants to eat.

And it's Especially, not specially.

Without grammar all you have is a bunch of words that might not mean anything beyond gibberish.

Here is another example of why grammar is important.
https://prezi.com/vg1zfpispze2/the-panda-eats-shoots-and-leaves-the-importance-of-commas/