No, that's a wrong statement. Grammar is the key to understanding and mastering English. Grammar helps us to understand how English works. Grammar brings order, logic, and clarity into the process of studying English. It specifies how sentences are built to make sense, identifies the meanings of individual words in a sentence and explains relationships between them, and gives you a set of rules for speaking and writing.

English grammar is quite rigid and strict. It has to be, because word meanings often depend on the grammatical constructions in which they are used.

well it depends, if you want to focus more in your  english speaking skills grammar is not as necessary as in writing skills.  In terms of conversations basic grammar is quite okay, but not really important. I had read in an english language website that if you want to have a good  english speaking skills you must try not to focus much with the grammar. 

Maybe you do not have to LEARN grammar , but definitely , you must KNOW grammar to speak well and write better . You should not be confined by grammar rules in case that you are trying to practice your English . All you have to do is just to get familiar with grammar and make grammar become your best friend  .  Besides , if you had a GOOD partner who can tell you when your grammar goes wrong and remind you any time , you can learn from this GOOD partner to KNOW grammar day after day . You can KNOW grammar from trial and error . I hope you may perceive if trial and error learning is more efficient than grammar learning .

Yes, It's true that grammer is not important while speaking or practicing English, There is a huge differrence in UK and US English because UK people always speak correctly in case of grammer.

Haan, I agree. To learn a language , you have to actually practice it. Grammar can come later.

For me, the best way to learn something is using trial and error method, I am allowed to make mistakes in order to know the right thing. :)