in order to know a foreign language thoroughly , four things are necessary. Firstly, we must understand the language when we hear it spoken. secondly, we must be able to speak it ourselves, with confidence  and without hesitation . Thirdly, we must do much reading. Finally, we must be able to write it. We must be able to make sentences that are correct in grammar. There are no shortcuts to succeed in language learning. A good memory is a great help, but it is not enough only to memorize the rules from a grammar book. it is not much learning by heart long lists (  ) of words and their meanings, studying the dictionary and so on. We must learn by using the language. If we are pleased with a few rules we have memorized, we are not really learning the language. We must "learn through use". Practice is important. We must practice speaking and writing the language whenever we can. Which is the most important in learning a foreign language?
a good memory. speaking. practice. writing.