What are the main ways to express opinion in Chinese? I know there are some verbs used for this, like 想, 觉得 and 认为. What are the difference between them when expressing opinion? (I know they also have alternative meanings but I am only interested when used to express an opinion or a thought.)
The three verbs have the quite the same meaning. Actually, you can use either of them as an equivalence. If you are really keen to the difference.
想- just like, "I think" 觉得 - I think things should be what I thought in mind, but not very sure 认为 - I believe things should be what I thought
hope it helps.
想，觉得：一般比较随意，是日常交流的 (maybe colloquial; I'm not sure)
PS： 我是中国的. (I am Chinese.)
English translation of the above:
想，觉得: they're ordinarily based on one's wishes, as in everyday communication (maybe colloquial; I'm not sure).
认为: usually more official, like a formal proposal or report, precisely explains one's thoughts.