I say—
1. is used preceding an utterance to call attention to it:
- Do you hear the rain, Mr. Caudle? I say, do you hear the rain?
2. is used as an exclamation of surprise, delight, or dismay:
- I say, what on earth are you doing letting your eight year old watch a TV show you don’t approve of?
Note: The expression does not correlate in meaning with the phrase I’m telling you—used to say smth. firmly to a person:
- You are asking me to donate money to the party and I’m telling you I will not donate one red cent.
I’ll say—(coll.)
1. is used to show complete agreement with what was said:
- “What a queer duck he is!” exclaimed Biff. “I’ll say he is!” ejaculated Chet Morton.
2. is used for emphasis:
- If they’re doing well in a class and I’m not (at least not as well), I’ll say it’s just because they’re working hard.