When I listen to English broadcast, I sometimes understand it, but I can’t write out the whole sentence.
Why should you want to write out a whole sentence if yoi’re listening to a broadcast? A broadcast is generally a flow of spoken English. It isn’t a dictation. What I think you’re really saying is that you don’t always grasp the meaning of individual words. My advice is this: when listening to spoken English don’t try to get the meaning of individual words. Concentrate on listening to complete sentences, trying to get the‘global meaning’where you can. This means you will have to guess the meaning of new words from the context. Train yourself to listen for meaning, not for words.