Multiple choice general knowledge math & puzzles Read the sentence to find out whether there is any grammatical error in it He wanted to work all night but we saw that he was completely worn and so we persuaded him to stop. No error. Reveal answer Fill a bubble to check yourself B Correct answer Explanation The phrase 'completely worn' is an incomplete idiom in this context. It should be 'completely worn out' to correctly indicate extreme exhaustion. The other parts of the sentence are grammatically sound.