About the use of ‘only’, I know 1. is correct, but how about 2.?
1. I don't know the song very well. I only know the name.
2. I don't know the song very well. I know only the name.
Comment: Either of these is fine, although as you may have guessed, "I only know the name" is far more common.
We can cross-reference this to such sentences as, "I don't think so" - which in modern English generally preferred to, "I think not."
PR