Who or whom?

There’s a continuing debate in English usage about when you should use who and when to use whom. According to the rules of formal grammar, who should be used in the subject position in a sentence, while whom should be used in the object position, and also after a preposition. For example:
長久以來英文裡一直有一個關於何時用who何時用whom的爭議，根據正式的文法規則who 應該使用來句子中的主詞，而whom應該被當作受詞，而且必須接在介系詞後面

Who made this decision? [here, who is the subject of the sentence]

Whom do you think we should support? [here, whom is the object of support]

To whom do you wish to speak? [here, whom is following the preposition to]

Some people do still follow these rules but there are many more who never use whom at all. The normal practice in current English is to use who in all contexts, i.e.:

有些人依然遵守著這些文法規則，但有更多人是完全沒使用過whom的

Who do you think we should support?

Who do you wish to speak to?