May be I'm able to crawl and walk a little, but I still can't run. I really appreciate the notes. If there are some books which may help, I hope that you can help me with. Thanks!

It takes a great deal of experience and practice. That's all you can say. First you crawl (understand and be understood). Then you walk (write correct, grammatical, well-phrased English). Then you run (speak correct, grammatical, well-phrased English on the fly). In the United States--it's international, but mostly in the U.S.--there is an excellent organization called Toastmasters that is devoted to helping people speak in public. They have a lot of exercises and practice. At every session they have a portion called "Table Topics," where you are handed a card with a subject--a subject you do not know in advance--and have to speak for five minutes about that subject. They also have three people listening to your speech: a "timer," a "grammarian," and an "ah counter." The timer makes sure you speak for a full four minutes--and cuts you off if you speak for six. The grammarian makes notes of every English mistake you make. And the "ah counter" literally counts every "um," "er," and "ah." This sort of thing helps a lot.

How could we have the ability to speak as we have when writing notes and compositions?

It is not clear what you are asking.