One who can't be bothered with speaking in full sentences until bedtime, when he becomes the most vocal, social, charming little person in the land. (mommyish.com)
Each 5th grade reading passage is followed by 5 - 6 questions which the student should answer by writing full sentences in the space provided. (k5learning.com)
It's also important to use full sentences in letters and emails. (targetjobs.co.uk)