发/h/音。

Whom does he like?

他喜欢谁

Whom do the police suspect?

警方怀疑谁

To whom did she address the letter?

那封信她是写给谁的

To whom should I address the letter?

这封信我该写给谁呢

To whom should I write?

我应该把信写给谁

Whom did they invite?

他们邀请谁了