I have a Japanese friend in Japan teaching English and she wrote me this email the other day asking for advice.........
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When I worked for Kumon writing English-study videos and their texts, we had a boss who insisted that "too" MUST be preceded by a comma, e.g.,
"Me, too."
I explained that the presence of the comma depended on the desired meaning.
For example,
1. ["She's beautiful."] ***"She's smart, too."***
=She is beautiful and also smart."
2. ["He's smart."] ***"She's smart too." ***
=He is smart and she is also smart."
We might take a view that "too"
with the comma addresses the predicate,
while "too"
without the comma addresses the subject.
Can anyone out there help her???? 'Cause I sure can't

thanks for your help