Which term describes the extent to which a learner's use of a second language conforms to the rules of the language, usually measured by grammatical accuracy?

• A. Accuracy
• B. Intrinsic modality
• C. Fluency
• D. Complement

Answer: (A)

The main concept here is accuracy in second-language use—the degree to which a learner’s output follows the language’s rules and grammatical conventions. When we talk about accuracy, we’re focusing on producing correct forms, agreement, word order, tense, and other grammatical features. This is what researchers and teachers measure when they want to know if someone is using the language with proper grammar, not just how quickly they can speak.

Fluency is the related idea that emphasizes smooth, natural, and effortless communication, which can involve speaking quickly and continuously even if a few errors slip in. The other terms listed don’t capture the grammatical correctness focus: intrinsic modality isn’t a standard measure of accuracy in SLA, and complement isn’t about language accuracy at all.

So, the term that describes the extent to which a learner’s use of a second language conforms to the rules, usually measured by grammatical accuracy, is accuracy.