This blog post links to other posts that feature printable worksheets, flashcards and coloring pages designed to help young students learn English letter N. I have published multiple posts like this to facilitate navigation through my blog for fellow EFL and ESL teachers looking for printable resources. Step by Step TOUCH.
It's a very good question. We should not attempt to speak any language unless we are sure about the grammar rules. Please buy a good grammar book to get the thorough knowledge of the rules. Do enough practice sessions. Spend minimum two hours ever.