I think that Chomsky's theory gives us more than a hint on how we acquire our L1. I agree on the fact that we learn the most difficult thing we are going to learn at a very early stage and without any effort( and not even realizing too). I have two little nephews( 3 and 1 1/2 year old), and I could see and compare how they acquired language. Creativity is always present and also both of them did not react in the same way to the same stimulus. Although they were raised in the same house, they did not have the same input. However, the eldest one( who was the one who received more input) took more time to start talking than the youngest. For instance, I agree on the fact that one stimulus has a lot of responses, and that we do not need a lot of input to start talking or to acquire a language.

In addition to this, sometimes I do not know where the eldest one takes the words he says. For me this has to do with the different steps that are mentioned in the book and that language comes from the inside, which also is our internal language. 

One of the questions that comes to my mind( which is also connected with a video I recently watched about when babies are in the womb), is whether babies can listen from the inside what people from the outside tell them, and whether that has to do with the language acquisition process. What is more, I wonder when our ears are developed, the L1 acquisition process starts from that point.

Mercedes Sánchez