Words which one recognizes when one hears or sees them are ________.

The correct answer is Receptive vocabulary.

Explanation:

Vocabulary is generally divided into two main categories: receptive and productive vocabulary.

1. Receptive Vocabulary (Passive Vocabulary): Refers to words that a person can understand and recognize when they hear or read them. People typically have a larger receptive vocabulary because recognition is easier than active retrieval.

2. Productive Vocabulary (Active Vocabulary): Refers to words that a person can actively produce and use correctly in speech or writing.

Since the question specifically refers to words that one recognizes upon hearing or seeing them, the correct term is Receptive vocabulary.