Knowing a word means that you are able to recognize the word's form (spelling, pronunciation), its meaning (concept, associations, mental image), and its use (level of formality, adequate context, various connotations). Al this aspects can be shown to students to direct teaching if vocabulary is treated as an integral part of a language curriculum. However, these does not guarantee that students will be able to use the words effectively. Mostly the words will be stored in their minds as bits of information.
One way to overcome this problem is to have students see the words repeatedly in a whole context. This is basicaly achieved through the implementation of reading. Learners also need to produce the words in several different contwexts ans this is what happens in speaking and writing