Here the mother may safely interfere, pushing the legs as they ought to go and showing the child how to manage himself; for very often he becomes much excited over his inability to creep forward. "Study of Child Life" by Marion Foster Washburne

I should think that this illness of his youth, and which, though of a fitful character, was of many years' duration, arose from his inability to direct to a satisfactory end the intellectual power which he was conscious of possessing. "Curiosities of Literature, Vol. 1 (of 3)" by Isaac D'Israeli

He regretted exceedingly his inability to oblige the ladies, but- and he prepared to drive off. "Abroad with the Jimmies" by Lilian Bell