One of the main difficulties people have is being self conscious. You have to learn to let go of what others think or what you think of yourself when speaking or trying to speak in your target language. Perfection is a process and not a destination. So the best way to overcome this is to speak more and more English, make mistakes and see if there is a pattern. And then tackle it and be accomplished in your own self. If someone puts you down it means they either have low confidence in themselves or do not know how to speak other languages anyway. So their opinion is still moot. Read many types of media in English. If you can read, say an article in a magazine, you still might not be able to read a classafieds clipping. It adds to your vocabulary. Try to take a few words a day and use them. Most of what people say are the same thing day in and day out. So by constant exposure you can literally sop up a lot of any language like a sponge. Read novels, write, either on here or in a journal or with a pen pal...find someone to text or just chat. Watch movies and episodes, listen to the radio....many stations are online. Speak with many english people. If there is a specific version you wish to hone in on, choose people that line up with that. British english has different vocabulary and pronunciation than american english. We can understand them overall, but a lot of their words we don't use or if we share it, it means something different. That is my advice anyway. Regardless, only by exposure to the language and talking to a variety of people can you increase actively your skills.

Basically: Speak whenever possible. If you're having particular problems with responding and answering questions, then you need to put yourself in the position where you have to answer questions, and respond to people. Which means you need to have more conversations with people. The more the better. Another thing you can do to just generally improve your general speaking ability -- speak, as much as possible. Speak with people online, speak with anyone you know you can. And finally, but also very useful - speak with yourself in English when you're at home. Here you don't have any problems of having to answer somebody immediately, you can take your time more. You can also find (or make up your own questions), and then answer them yourself by speaking - try recording your own voice to listen to afterwards.

By speaking with the native people

@DUCK & @Teresa : Let's learn :)

I have same trouble with you.