If you go and ask in the streets, everyone will say that they know English. But when asked to speak, they cower. Why? 

• They are afraid that they will make a mistake. They are shy because they think that making those mistakes will embarrass them.
• They think their pronunciation is bad.
• They want to speak perfectly so they think too much while talking.
• They think in their native language, so they cannot form a sentence as complex as they want.
• Absence of grammar.
• When they are first taught English at school, it was not focused on talking, it was mostly about how to write or how to form a sentence.
• They have no practice, meaning they do not talk in English or do not have the chance to.
• Lack of vocabulary.
• They see English as a lesson only and they are not interested in it.