The first-order sentence $\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$, whose propositional form is $p \land \neg q$

Terms

Term	This example	Why
sentence	✓	$\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$ is a sentence, because the quantifiers $\forall x$ and $\exists x$ bind every occurrence of $x$.
formula logic	✓	$\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$ is a formula of first-order logic, because $\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$ combines two quantified formulas about the number $x$ with $\land$ and $\neg$.
propositional formula	✗	$\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$ is not a propositional formula, because its parts are quantified statements about numbers, not propositional variables; replacing $\forall x \, (x^2 \geq 0)$ by $p$ and $\exists x \, (x^2 < 0)$ by $q$ gives the propositional formula $p \land \neg q$.

Sentence vs. propositional formula: The sentence $\forall x \, (x^2 \geq 0) \land \neg \exists x \, (x^2 < 0)$ has the propositional form $p \land \neg q$: the propositional formula records only how the statements are combined, and the sentence also says what the statements are about.