dont worry a child whom cant speak for first time is as same as us to learning a new language but he/she step by step go forward till he/she will become a full native speaker
therfore you can understand it step by step:
1. take some movies with english subtitle
2. when they soeak some thing you can see their sentences
3.puse the tape or dvd repeat them till you can say it as same as them
4.try listen english every time even in sleeping ( it helps you to be more familier with it).
5.speak out after your listening not only in your mind but also with your tongue
dont worry every of us start from low level