Vocabulary Acquisition and Use4. Determine or clarify the meaning of unknown and multiple-meaning words and phrases based on grade 1 reading and content, choosing flexibly from an array of strategies.a. Use sentence-level context as a clue to the meaning of a word or phrase.b. Use frequently occurring affixes as a clue to the meaning of a word.c. Identify frequently occurring root words (e.g., look) and their inflectional forms (e.g., looks, looked, looking).