1. Prone / liable / subject + to
Look at the sentences from the passage The credit card trap.
(1) They target people who are prone to impulse-buying, and potentially bad credit risks, tempted to spend more than they have, and liable to fall behind with repayments.
(2) …her bank had written to her offering a credit card at a low interest for a trial three-month period, subject to suitability…
Prone, liable and subjected + to are similar in use and meaning. They can all indicate a likelihood that something will happen. Prone to tends to be used to describe things which happen to someone that are beyond their control, such as illnesses. Liable to indicates that the likelihood of doing or saying something because of a fault or natural tendency. Subject to can indicate that something is necessary according to a rule or law.
Let’s do some exercises.