To quickly verify grammatical objects on your exams, use the standard pronoun replacement test:
$\text{If a word can be replaced by \textbf{it/them} (things) or \textbf{him/her} (people), it is functioning as an object.}$
Verify that the Indirect Object always precedes the Direct Object in standard word order: $\text{Verb} \to \text{IO} \to \text{DO}$.