Language learning is based on receptive skills not the productive ones

Learning languages is based on receptive skills as from reading and listening learners can build the following skills and abilities.

Language learning = Reading+ listening+ writing+ speaking+ grammar+ pronunciation+ vocabulary.

Look if one of us concentrate on listening and reading, he/she can solve 5 elements of language (Reading+ listening+grammar+ pronunciation+ vocabulary) what represent more than  71% of language learning. Then, they will acquire language reservoir to use to produce language (in speaking and writing). Without this reservoir, no one can be able to produce language either through speaking or writing (reservoir is grammar, vocabulary and pronunciation that we gain through receptive skills)