unlike

Unlike is an English word with two primary grammatical functions: as a preposition and as an adjective. It expresses dissimilarity or difference between two things or groups, and it is used in both formal and everyday writing.

As a preposition, unlike introduces the thing that differs. Examples: “Unlike the other candidates, this option is cheaper.” It can take a noun phrase (“unlike most teenagers”) or a clause (“unlike what I expected”). It is often placed at the beginning of a sentence to emphasize contrast.

As an adjective, unlike means “not alike” or “dissimilar.” Example: “The two plans are unlike in their approach.” This use can modify nouns directly or describe a relationship between items.

Usage notes: Unlike tends to highlight a meaningful, defining difference rather than a mere difference of opinion. It can be more emphatic than phrases like “different from” or “not like” in certain contexts, and it is common in both written and spoken language when a clear contrast is intended.

Etymology: Unlike is formed from the negating prefix un- attached to like. The construction is historical in English and reflects a straightforward way to express non-similarity, with usage dating back to Middle English and earlier roots in Germanic languages.