I can write upper case letter M
I can write lower case letter m

Uppercase!

M-M-Moon
M-M-Monkey
M-M-Muffin
M-M-Mouse

Oh, I know so many words
That begin with the letter M

Lowercase m

m-m-moon
m-m-monkey
m-m-muffin
m-m-mouse

Oh, I know so many words
That begin with the letter m