彼女は何か食べ物が欲しいです。
この犬は何か飲み物が欲しいです。
彼は何か読み物が欲しいです。
I didn't understand this structure, could you write some translations and explain me them?
何か can be used like a noun (It's a 代名詞/pronoun), meaning "something", as in:
- 何かがありそうだ。 There seems to be something.
- 新しい何かを手に入れることは古い何かを手放すことだ。Getting something new means giving up something old.
Now regarding your examples, 何か is often used in the form of 「何か + noun を/が + verb」, meaning "[verb] some kind of [noun]", as in:
- 何か + 仕事を + ください。 -- lit. Give me some sort of job.
- 何か + 商品を + 買う -- lit. buy some kind of product
- 何か + 食べ物が + 欲しい -- lit. want some kind of food → want something to eat
- 何か + 飲み物が + 欲しい -- lit. want some kind of beverage → want something to drink
Therefore your sentences:
- 彼女は何か食べ物が欲しいです。 lit. She wants some kind of 食べ物(=food) → She wants something to eat.
- 彼は何か読み物が欲しいです。 lit. He wants some kind of 読み物(=thing to read) → He wants something to read.
The 何か here is adverbial, so it's not modifying the nouns 仕事(job), 商品(goods), 食べ物(food), but the verbs/adjectives 「ください」「買う」「欲しい」 here. You should say 「何かの+noun」 to literally say "some kind of [noun]", as in 「これは何かの冗談ですか?」(or 「これは冗談か何かですか?」) (Here 何か is a pronoun) to say "Is this some kind of joke?", rather than 「*これは何か冗談ですか?」
何か is also used in the form of 「何か + verb/adjective + もの」, meaning "something [adjective] / to [verb]", as in:
- 何か + 買う + もの -- something to buy
- 何か + 食べる + もの -- something to eat
- 何か + おいしい + もの -- something tasty
- 何か + いい + もの -- something good
So you can rephrase your example sentences this way without changing the meaning:
- 彼女は何か食べる物が欲しいです。 lit. She wants something to eat.
- この犬は何か飲む物が欲しいです。lit. This dog wants something to drink.
- 彼は何か読む物が欲しいです。lit. He wants something to read.
何か in this case means "some" or "something":
何か食べ物 some food
何か飲み物 something to drink
何か読み物 something to read
何か means "something", so the first one means "She wants something to eat". Presumably this will help you with the rest.