Since my actual name is Robert and Bob is not my correct name then no Bert doesn't. But if you count Bob as my name that's what I write and say 99.9% of the time.
It starts with the first letter of your first name.
It does not start with the first letter of your first name.
Since my actual name is Robert and Bob is not my correct name then no Bert doesn't. But if you count Bob as my name that's what I write and say 99.9% of the time.