Probably the same as anyone else. English is a very difficult language for a non-native to learn - it's full of irregularities and odd pronunciations. If you can, have regular times when you can practice your English in conversation with a native speaker of the language. That will teach you at least as much as you could learn from a book. If you don't have easy access to a live person, listen to English conversation recordings. Also, keep in mind that American English is different from British English.
Tenses, accent, spelling, pronunciation are among the many common errors Pakistan English learners and users make. These errors also occur among all other English users. All this errors can be avoided if the English language is used or practiced regularly.