Final answer:
In the given sentence, 'Sunday' and 'cake' are the common nouns. A common noun refers to a general, unspecified person, place, or thing. 'Grandma', though often a common noun, is acting as a proper noun in this context.
Step-by-step explanation:
In the sentence 'May I stay with grandma on Sunday? I want to help her bake a cake', the common nouns are 'Sunday' and 'cake'. A common noun is a word that refers to a general, unspecified person, place, or thing. In this context, 'Sunday' is a common noun indicating a day of the week and 'cake' indicates a general type of food. 'Grandma' might seem like a common noun, but in this context, it's used as a proper noun because it refers to a specific person, namely the speaker's grandmother.
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