o-grid help
 

Actually, I want to create a c-grid. Conventionally, the C-grid can be created through a O-grid with a face attached. However, my situation is annoying, shown in the attachment (simplified). Specifically speaking, i want to create the C-grid in the left part with the right part intact.

please give me some advices or strategies! thanks a lot!

you can merge vertex to realize what you want

Thank you, sir. But it seems quit differently from the prescribed. Would you please give me another solution or the improvement. It would be best that the effect i described could be achieved.