According to linguists (those who undertake the scientific study of human language) there is an important distinction between language acquisition and language learning.
So what is the difference?
The distinction is made based on an individual’s internal cognitive process and the degree of conscious thought brought to the learning task.
Children acquire language through a subconscious process during which they are unaware of grammatical rules. This is similar to the way they acquire their first language. The emphasis is on the text of the communication and not on the form.
In a second-language acquisition situation, the language is spoken in the immediate environment of the learner, who has good opportunities to use the language by participating in natural communication situations.
Language learning, on the other hand, is not communicative. It is the result of direct instruction in the rules of language and is not an age-appropriate activity for young learners. In foreign language learning, the language is not spoken in the learner’s immediate environments and the student has little or no opportunity to use the language in natural communication.