ICLS Standard II Fluency, Vocabulary Development, and Comprehension Practice Test

The growth of a person's stock of known words and meanings is vocabulary development. This term captures how a person’s mental lexicon expands as they encounter and learn new words, along with their meanings, through reading, talking, and study. Among the options, it best fits because it focuses specifically on expanding word knowledge. Fluency deals with the speed and smoothness of reading or speaking, not how many words a person knows. Phonology concerns the sound system of a language and how words are pronounced. Comprehension is about understanding meaning, which depends on vocabulary but is broader than just growing word knowledge.