The Story of English in 100 Words by David Crystal

" productive skills are a bit harder to pin down because even more psychological and social factors come into play," says Coontz. "Ease, finding your own voice, finding a sense of fluency, that's learning the grammar, being able to use it right without making mistakes." So how do you work on these things is the question. Are you using a wide range of language for almost anything? Can people follow you easily as a whole text? And Social factors like knowing how to put things together in relationships through language?"