Modal Verbs Error Correction

This modal verbs error correction exercise targets the mistakes learners make most often when proofreading complete sentences: adding to or s after a modal, confusing obligation, prohibition, and no obligation, and using the wrong modal form for deduction, future ability, or past regret.

Wrong: "She can speaks confidently in meetings." Correct: "She can speak confidently in meetings."
Wrong: "You don't have to enter this room; it is forbidden." Correct: "You mustn't enter this room; it is forbidden."

Because this page asks you to click and repair only the wrong chunk, it trains a different skill from normal gap-fill modal practice. You must read the evidence in the whole sentence, decide whether the modal expresses ability, advice, obligation, permission, deduction, or regret, and leave the sentence alone when the modal choice is already correct. That protects you from over-correcting valid forms such as polite could requests or uncertain might be deductions.