VOA慢速英语:Have You Met the Perfect Tenses?

participle - grammar. a form of a verb that is used to indicate a past or present action and that can also be used like an adjective

adverb - grammar. a word that describes a verb, an adjective, another adverb, or a sentence and that is often used to show time, manner, place, or degree

indicator - n. a sign that shows the condition or existence of something

scared - adj. afraid of something