"They've kept up with it better than I was able to at that age."
And you really should be able to, at this stage.
Maybe the head was able to chip away at it.
I thought we might be un- able to work at all!
She hadn't been able to let him touch her, not at that moment.
"Then how was he able to come up with an answer at all?"
I only seem to be able to book on ticket at a time.
But I probably wouldn't have been able to sleep even in my bed at home.
She'd always been able to laugh at herself, and she did so now.
This continued until he was able to race cars at the age of 16.