I just stumbled across an article from The Economist and had to share this quote about one of the most important strategies for achieving fluency in language learning: chunking. Chunking is thinking about and studying the language in common phrases, instead of single words.
A common example is good morning . We don't have to learn the word good and then the word morning and put them together: we simply learn it as a phrase, and we can say it quickly, without thinking much.
This can be applied deliberately to other phrases, too though. Here are some common phrases you might want to study as chunks:
on the other hand
contrary to popular belief
the thing about that is