Lest vs. Unless

Lest vs. Unless — Is There a Difference?

Difference Between Lest and Unless

Lestconjunction

For fear that

tiptoed lest the guard should hear her.anxious lest he become ill.

Unlessconjunction

Except on the condition that; except under the circumstances that

"Exceptional talent does not always win its reward unless favored by exceptional circumstances" (Mary Elizabeth Braddon).

Lestconjunction

So that someone or something not; in case someone or something might

"Lest anyone forget, adolescence is purgatory" (Jon Pareles).

Unlesspreposition

Except for; except.

Lestconjunction

For fear that; that not; in order that not; in case.

He won't go outside, lest he be eaten by those ravenous eagles.

Unlessconjunction

Except on a specified condition; if not.

I’m leaving unless I get a pay rise (AmE: raise).

Lestconjunction

That (without the negative particle); – after certain expressions denoting fear or apprehension.

Unlessconjunction

If not; used with counterfactual conditionals.

Lestadverb

for fear that;

she tiptoed lest her mother should hear her

Unlessconjunction

Except if; used with hypothetical conditionals.

Lestadverb

that (after verbs explicitly expressing fear etc.);

he worried lest he should be late