How the Idea of the Language of Thought Is Evaluated by Wittgenstein?

In Philosophical investigations, Wittgenstein criticizes many classical and contemporary philosophical theories about language. Here, with a brief presentation of what is called as the theory of "language of thought" (or mentalese), I will try to show why this theory is also rejected by Wittgenstein's conception of language. For this purpose, my efforts will be focused on answering these questions, according to Wittgenstein: What is called "thought" and what is its relation with language? Is thought a purely mental process? Is language just an instrument to convey thought? Does thought precede language or is it not independent of language? If thought is not independent of language, do humans have something as mentalese, or the language of thought, before learning a language? Finally, I will try to show Wittgenstein's objection to the theory of the language of thought falls under which set of objections to this theory and what is the response of proponents of the language of thought to this objection and how is this response evaluated.