Declarative knowledge is __________

Declarative knowledge ("knowing THAT") refers to a learner's conscious, factual awareness of language rules and information — being able to state or recall a rule. It is distinct from procedural knowledge ("knowing HOW"), the ability to actually apply or use that rule fluently in real communication, without necessarily being able to explain it.

In this item, the option describing knowledge about the grammatical item matches declarative knowledge — it is knowing a fact or rule about the item, not performing any action with it.

The remaining options each describe procedural, performance-based abilities:

• Pronouncing a word correctly: actually producing the sound is a performance skill.

• Identifying an error in a grammatical item: applying a rule to spot mistakes is an active use of the rule.

• Using (doing) the grammatical item: producing or using it correctly is performing it.

Therefore, only knowledge about the grammatical item — a fact or rule one can state — is declarative knowledge; the remaining options describe procedural, performance-based abilities.