In order to know a foreign language

In order to know a foreign language thoroughly(完全地), four things are necessary. First, we must
understand the language when we hear it spoken. Secondly, we must be able to speak it ourselves,
correctly with confidence(自信) and without hesitation(犹豫). Thirdly, we must be able to write it. We
must be able to make sentences that are correct in grammar.
There is no short way to succeed in language learning. A good memory(记忆) is a great help, but it is
not enough only to memorize the rules from a grammar book. It is no much use learning by heart long lists(一览表) 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 practise speaking and writing the language
whenever(无论何时) we can.