Coming from the こそあど言葉（ことば） family of words, こう
, or どう
may be used with the verb 言（い）う to form an expression which literally means ‘in the way of (A)’. (A) being ‘this’ これ
, ‘that’ それ
, ‘that over there’ あれ
, or ‘what’ どれ
(in questions). As with all pre-noun adjectival words, this expression will be used directly before a noun.
This is my first time watching a movie like this. (This ‘kind’ of movie)
I don't like people like that. (That ‘kind’ of people)
I want to try to drive a car like that one. (That ‘kind’ of car)
What kind of music do you listen to?
, and どう
share a relationship with これ
, and どれ
, they are their own individual words, which each have a meaning similar to ‘as such’. These words are all 副詞（ふくし） (adverbs) when used by themselves.
そう (the adverb), should not be confused with そう (the auxiliary verb). そう (the adverb) comes from the kanji 然（そ）う, while the auxiliary verb does not have a kanji form.