Microsoft Word has a built-in grammar checker, and there are some separate programs available. Aside from being a native speaker of English, that is the only way you are going to produce a decent paper.
Folks writing an English computer translation program estimates there are 18,000 grammar rules in English. Reading books that are commonly used in English literature classes are the way native speakers get a feel for these rules. Only certain books are important. The most important author is Ernest Hemingway. He is acknowledged as having the best overall style of writing. Read and imitate his style, and you will impress people.
Above all, keep your sentences short. Long sentences are a sure fire way to pick out a non-native speaker of English.