Search from various English teachers...
Pelin
Which on is OK? I'm sorry I can't be more help. I'm sorry I can't be of more help. I'm sorry I can't be more helpful.
Jan 28, 2018 2:45 PM
Answers · 4
All three are good. I wouldn’t split hairs on the differences. To do so is just a waste of time.
January 28, 2018
The first one is not correct!

The second one sounds good and it is acceptable to be used in a sentence, but the third one sounds more natural and it is more commonly used!

Best option: "I'm sorry I can't be more helpful"

Hope that helps!

January 28, 2018
Even though the third one sounds more natural, the second one is also acceptable.
January 28, 2018
I believe third one is better than others.
January 28, 2018
Still haven’t found your answers?
Write down your questions and let the native speakers help you!
Pelin
Language Skills
English, Turkish
Learning Language
English
Articles You May Also Like
Same Word, Different Meaning: American, British, and South African English
10 likes · 7 Comments
How to Sound Confident in English (Even When You’re Nervous)
12 likes · 9 Comments
Marketing Vocabulary and Phrases for Business English Learners
9 likes · 2 Comments
More articles