Q:

Some questions about the use of となる

According to what I read, となる is the written counterpart of になる. Nevertheless, I stumbled upon some use of となる that seems not to fall under the typical usage of になる (which, for me, means "to become" as in 講師になった).
Sometimes となる seems to be used in place of the copula です. (Ex: 考{かんが}えを述{の}べる表現は「〜と思う。」となる)
Another use that I do not understand can be found in this example:  

動詞は、述語 となる 三つの品詞の中で最も変化に富むもので、その文型もさまざまな種類があり ますが、動詞文の最も基本的な型は、次のように表すことができます。  

in paragraph 1.1.3 動詞文 of 基本述語型と修飾語 
Thus, my question is what do mean those usages of となる? And is there any other usage of となる?

A:

Like your example 述語となる品詞 already suggests, I've always understood it like this:
Whereas になる underlines a process of transformation from something to something, となる is more used when expressing "make up, equal, take the position of".
I.e. 教師になる means the end of the transformation "from student to teacher", whereas 教師となる would mean "take the position of teacher".  

