"could be able" is correct and usable in written English.
You can use it when you want to indicate potential capability. For example, "I could be able to finish the project by the end of the week."
If the transplant holds, she could be able to get pregnant.
"I feel good that I could be able to stand up for my team," Strickland said.
"Something which I never thought I could be able to say about a plane is: next stop Salina".
As with other types of insurance, you could be able to cut your premiums by taking on a bigger excess.
The deadline means that several Central European and Mediterranean countries could be able to join in 2004.
"While the company could be able to pull through unscathed, the market is giving little credit to do so".
It could be able to suggest whether a user wants to read each message that comes in.
According to Mr. Auerbach, you could be able to borrow up to four times your annual income.
9.13am BST Apple's 'iWatch' could be able to control your home Apple's iWatch could be capable of controlling your home automation kit.
Such biological computers could be able to handle very large numbers of analytical steps simultaneously, a process called parallel computing, and might be able to do that cheaply.
The NTC fears Gaddafi loyalists could be able to mount attacks easily across the border and then escape back into Algerian territory.
