Student-generated questions in relation to text were examined in two studies. Study I examined the impact of student questioning in relation to general vocabulary in English-Only Speakers (EOs) and English language learners (ELLs). Findings indicated that questioning predicted comprehension in the reading comprehension of both groups of readers, albeit different patterns were found in relation to general vocabulary. Study II explored the specifics of questioning instruction revealing that ELLs with varying reading levels improved their questioning skills after instruction and there was an association between question types and reading comprehension. Collectively, both studies indicated that text-based student questioning is a reading strategy that contributes to ELLs' reading comprehension and conceptual knowledge in the content area of science. Implications for content-area reading for ELLs are discussed. (Contains 6 tables and 3 figures.)