2.1 Origin of language
The interesting thing about language is that the evolution of different styles of language is preceded by and makes evolution possible for the ability to speak. First there has to be a primitive cries/sounds before a more complex language form can be designed.

If we study the dual-inheritance theory to regard as the evolution of culture phenomenon’s are connected with the biologic evolution of organism. The evolution of language can be explained as follows.

Through developing of our speech organs, hearing organs and human brains people have been able to produce and sense more various sounds and use them for communicative purposes with meaning and grammar. This enables us to not only learn and teach our mother tongue but also other languages.

http://www.kennislink.nl/publicaties/evolutie-kan-ook-oorsprong-van-taal-verklaren

In my opinion thinking is faster. Because you will think more abstract. Just about the topic and what you want to share about it with someone else, without grammar rules etc. So in order the transform  that thought to good sentences these blocks of words are put together very fast, so they make a good organized sentence you can produce with speaking.

I found this very nice article that gives an insight about the differences between introvert and extravert persons about thinking and speaking.

According to this article an introvert person is not able to think and speak at the same time in contrast to an extrovert person who is able to think and speak at the same time.
The introvert person will give himself some time to think, before answering. An extrovert person often gets the ‘new’ ideas during talking. This talking helps him to think. (Foeken, 2013)

http://www.selmafoeken.nl/2013/12/de-4-grootste-verschillen-tussen-een-introvert-en-een-extravert.html

2.3 Dreams

Do you dream language? What/how do you dream?
Yes I do, because I have the senses to hear and speak a language. What or how, I don’t know. Sometimes I wake up and can recall everything I dreamt about in contrast to other nights when I cannot recall anything at all or just  partly.

(How) do blind/deaf people dream?
They dream with their other senses: feel, taste and smell.  But it depends if that person is blind/deaf from birth  or if this person became blind/deaf om a later age.

According to professor F. Lopes da Silva do blind people have an active visual system and are able to have ’ virtual dreams’ without seeing the images. Example: Blind people know what the shape of a square is and are able to visualize that in their minds, without having ever seen a square.

Another nice fact is that people who become blind/deaf after their 7th birthday will remain having sounds and images in their dreams for ever. (Tim Kraaijvanger, 2011)

http://www.scientias.nl/hoe-droomt-iemand-die-blind-en-doof-is/