Loading
LingakuLingaku何 + です 何 + [particle] 何 + の + [noun] 何 + [counter]
何 means "what". It goes in the place where the answer will go, not at the front of the sentence, and the question ends in か. The basic reading is なに. In front of です it shortens to なん.
It is なん before です, だ and の, and before a counter. Before most other particles it is なに.
Alone, as a one-word question, it is usually なに.
何 does not normally take は, because what you are asking about cannot already be the topic. It takes が or を.
To ask about the object of a verb, put 何 where the object would be and keep the particle. Here it is read なに.
These go beyond asking "what".
With a counter, read なん, 何 asks "how many" or "which": なんじ (何時, what time), なんがつ (何月, which month), なんさい (何歳, how old). なんにん何人 shows why the reading matters: read なんにん it asks how many people, read なにじん it asks what nationality.
何か, read なにか, is "something". 何も, read なにも, with a negative is "nothing".