There are some famous theories that discusses the development of language in little children. Some different perspectives of the same development of languages seems to contradict each other and this is truly interesting as the one unified thing such as languages is seemed to be developed by people in different ways. For instance B.F. Skinner believes that language is developed through positive reinforcement of language, that is when a baby babbles 'mama', the mother smiles therefore re-enforcing the child's learning. But on the other hand Noam Chomsky disagreed suggesting that children are born with an innate language acquisition device congenital understanding of deep structure of language which is its grammar. The idea of positive affirmation and re-enforcement the development of language defiantly stands true as children understand simple things such as smile and therefore get a lot of the simple language. Whereas children are unlikely to be born with such innate language acquisition device, as such thing would perhaps be to complex for the baby. Children however start to pick up most of the grammar that they learn and the words that they lear by listening. That is the key to a child's development in language. An example of this would be my cousin who as he grew never spoke a word but at the age of two or three, he was sitting with my dad and said "Look at how beautiful the roses are", now that suggests that he was always listens and putting two and two together in his mind and understanding the little wonders around him. He never spoke until that stage and most of us thought he couldn't speak but when he did speak, he spoke a whole sentence which threw us all off. Well both Skinner's theory of positive reinforcement seems to stand false as he never spoke till then but on the other hand Chomsky theory of inherit understanding of the grammar could possibly seem true at that point. But the idea of children understanding and learning through listening is also important and significant. This explains why children generally
learn to speak the mother tongue fairly well but might have problems reading and writing. This is because parents might speak the mother tongue at home which makes the kids understand and comprehend by listening and seeing. Kids are able to assume, guess and put things together to understand the language and if it is correct then parents positively re-enforce the idea. So therefore perhaps both of the theories come together to understand the development of language in children but essentially the idea of listen and understanding is also a major aspect of the development of language in children.
The idea of thought before speech or speech before thought has essentially become a great topic for debate, however it only seems logical to think before you speak. Language in thought is essential to speak. There would be no understanding if there was no language in thought. Everyone thinks in a certain language be it english, arabic, french or Canadian english. If you take away that language the thought seems impossible for language is a medium through which thought can take place. If there is no language there can possibly be no thought. The idea of thinking without language seems impossible but however that sparks the debate on how deaf people think or how babies think. The human brain tends to process information through the use of the five senses and therefore a babies thinks in the aspect that they are born with which is the eyes. There is a sense of visual understanding and visual thought in young babies and in the deaf even in grown humans when describing something abstract such as peace or love the picture of a dove or a heart pops to mind. Also for someone who is blind and deaf like Hellen Keller, when she was presented food in the movie "The Miracle Worker", there was a sense of recognition with that food. She might not have necessarily know what the name of the food was, but she recognised the food by smell. Hence there was a recognition, therefore for people who know language thinking using language as a medium seems essential but even people without the knowledge of language have some sense of recognition through medium of the five senses.
Going back to the theory of children's having the ability to listen and understand by putting things together explains why during the holophrastic stage, the child speaks sentences using single words. This is probably because of the child's association of that word with an action. The child has understood that the word means a certain action and therefore speaks sentences in single words. Also when the child says such single words such as 'more' and the parent gives more of something, through the idea of positive re-enforcement, the child then tends to say 'more' to get more of something. The child has associated the word with the action and this association in the mind of the child has brought about a sense of understanding for the word and it's action and causes the child to say the single word to get the output. If the child is given more of something by saying 'more', why would the child need to say 'can i please have more?', if the result is the same. Obviously it is nicer to ask the the latter way but the child isn't processing a lot of the language at such a stage and is taking baby steps into the realms of language.