Many verbs refer to feelings—for example, bore, confuse, excite, fascinate, frighten, interest. The present and past participles of such verbs can be used as ordinary adjectives (see 31l). Use the past participle (which usually ends with -ed) to describe a person having the feeling.

The frightened boy started to cry.

Use the present participle (which usually ends with -ing) to describe the thing (or person) causing the feeling.

The frightening dinosaur display gave him nightmares.

Be careful not to confuse the two types of adjectives.