To determine if students at this age would know the difference between nouns and pronouns, we can consider the normal curriculum and expectations for 3rd graders. In most educational systems, the concept of nouns and pronouns is typically introduced in earlier grades, around 1st or 2nd grade. By 3rd grade, students should have a solid understanding of the difference between these two parts of speech.
However, it's worth mentioning that students may still make mistakes or struggle with identifying nouns and pronouns accurately. In this case, the teacher's feedback indicates that the student circled pronouns (e.g., "I," "you," "he"), which are a type of noun but not common nouns.
Regarding whether the teacher should have specified "common nouns," it may depend on the specific instructions given to the students. If the teacher explicitly stated to circle the "noun" without any qualification, then technically, the student did not follow the instructions correctly. However, if the teacher only mentioned "noun" without further clarification, it could be beneficial to explicitly specify "common nouns" next time to avoid confusion.
In summary, it is reasonable to expect 3rd graders to know the difference between nouns and pronouns. However, considering the potential for mistakes, providing clearer instructions can help ensure students understand the expected response.