Language development in humans is a process starting early in life. Infants start without knowing a language, yet by 10 months, babies can distinguish speech sounds and engage in babbling. Some research has shown that the earliest learning begins in utero when the fetus starts to recognize the sounds and speech patterns of its mother's voice and differentiate them from other sounds after birth.
Typically, children develop receptive language abilities before their verbal or expressive language develops. Receptive language is the internal processing and understanding of language. As receptive language continues to increase, expressive language begins to slowly develop.
Usually, productive/expressive language is considered to begin with a stage of pre-verbal communication in which infants use gestures and vocalizations to make their intents known to others. According to a general principle of development, new forms then take over old functions, so that children learn words to express the same communicative functions they had already expressed by proverbial means.
Children learn syntax through imitation, instruction, and reinforcement. The instruction proposal is when the parent tries to correct the child, but ultimately the child does not apply it. There is key evidence against this because for example if the kid is saying "Want other one spoon," the parent will instruct the idea to say the right thing by stating, "You mean, you want the other spoon. Then the kid will respond and say "yes, I want other one spoon." Then the parent will say "Can you say "the other spoon." The kid will say "Other... one... spoon." Then the parent will try again and break it up for them. First they will get the child to say "other" and then say "spoon." Then after the child repeats it back to them, they will say "other... spoon" with a pause, but then the child will say the entire thing again and repeat it the wrong way, thus stating, "now give me other one spoon." From this, we can see that the child is unable to understand language and grammar.
