In a discussion about favorite subjects, you might say: Math is less enjoyable than Science.
When discussing chores, you might say: Washing dishes is less fun than vacuuming.
| Mistake | Correction |
|---|---|
| She is less smart than | She is not as smart as |
| This movie is less good | This movie is not as good as |
| He is less tall | He is shorter |
No, use it specifically for comparisons of degree or quality.
It is suitable for both formal and informal contexts.