| Oh | O |
| Usage:
1. Use O when it has a strong connection with the words that follow (i.e., when there is no comma after it). O mighty motor-mouthed one…. 2. Use Oh when it is an independent exclamatory utterance (i.e., when there is a comma or exclamation mark after it). Oh, what a bunch of twaddle! |
| Quotation:
"The present tendency is to restrict Oh to places where it has a certain independence and to prefer O where it is proclitic or leans forward upon what follows."
(Source: Fowler's Modern English Usage s.v. "O and Oh") |