Stephen Krashen also states another interesting hypothesis, where he makes a clear distinction between the terms “acquiring” vs. “learning” a language.

He says that acquisition is the natural, subconscious way of learning, such as a child learns her mother tongue. When we acquire language, we are not aware of all the rules to say something; we are so concentrated on communication, that our analytical mind is left behind. That is the moment we feel the language; we are able to tell if something is right or wrong by the way it sounds, by the way it feels, and we acquire a higher competence.

By “learning” he refers to the conscious learning of how the language works, that is, the grammar, the rules. This is “knowing about” the language, and in the long run, it helps us gain accuracy consciously, but in the beginning we may get lost in editing as we speak. Some theorists say that only young children can acquire language, and adults can only learn languages, but TPRS has demonstrated that acquisition is a powerful tool even for adults.

“…The result of language acquisition, acquired competence, is also subconscious. We are generally not consciously aware of the rules of the languages we have acquired. Instead, we have a "feel" for correctness. Grammatical sentences "sound" right, or "feel" right, and errors feel wrong, even if we do not consciously know what rule was violated.” S. Krashen18

As we said before, language is acquired through comprehensible input. If messages are not understood, nothing will make sense.

When we are teaching, our language should be repetitive, interesting, and varied.

18 Communication during a TPRS Conference in Cancun, Mexico, June 2011