If everyone who speaks Chinese also speaks English and at least one person does not speak English, then somebody does not speak Chinese.
Let C(x) and E(x) denote "x speaks Chinese" and "x speaks English", respectively.
Is my translation correct?
$$\forall x~\Big[\exists y~\big[ (C(x) \to E(x)) \land \lnot E(y)\big]\Big] \to \exists x~\big[\lnot C(x)\big]$$
Could you explain if the sentence is valid? (I think it is.) I dont need the proof.