Use "Lest" for Cautions

Speak softly lest you wake the baby.

Patternsspeak — spoke — spoken^wake — woke — woken

Check your work lest you make errors.

Patternsmake — made — made

Drive carefully lest you have an accident.

Patternsdrive — drove — driven^have — had — had

Save your document regularly lest the computer crashes.

Keep silent lest you betray your feelings.

Patternskeep — kept — kept

Study diligently lest you fail the exam.

Secure all valuables lest they be stolen.

Patternssteal — stole — stolen

Eat healthily lest you become ill.

Patternseat — ate — eaten^become — became — become

Cover the plants lest the frost damages them.

Wear a helmet lest you injure your head.

Patternswear — wore — worn

Let us leave early lest we get caught in traffic.

Patternslet — let — let^leave — left — left^catch — caught — caught