I've heard the use of 'but a' like this:
- I am but a common man.
- He is but a clever dog.
I'd expected something like this:
3. I am anything but not a common man
4. He is nothing but a common dog.
(Side question, what are the words anything, nothing in the sentence called?)
In the absence of words like anything, nothing, I'm unable to make sense of the sentences. Does it imply that he is a common man or not? Same for the dog, clever or not. What does the phrase
but a imply here? Please tell me about it's usage.