improve my english speaking skills

Technically this is not a programming related question and also, this is not an on-topic question because it targets building good English skills. Anyways, English is a language, and to learn it you would have to use it. You can find English forums, websites like C# Corner, where you can communicate in English.

 

Then, try to write some articles, blogs and other posts. Read posts and articles made by other authors. You will get a lot of information about good "grammar" and good "sentence structure" by reading those guides.

 

In the end, it is you, who are going to focus on learning. There are many online platforms that provide such a service. :-) You can get one, for free!