only

It’s significant that the closest relative of only is the word one: only always serves to distinguish one thing, group, or quality from others.

As an adverb only limits the application of verbs and adjectives: This area is reserved for members only.

Before nouns, only suggests singularity: She’s an only child. Is that the only shirt you have to wear?

In writing, only precedes the word it modifies; in speech, the word is emphasized, lessening the importance of position.

Listeners who hear, “I could only see three people there,” understand that the only goes with “three” and not with “see.”