Understanding the Difference Between -ed & -ing Adjectives

Adjectives ending in -ing and -ed are very common in English.
They look similar but have different meanings:

• -ing adjectives describe people, animals, things or situations that cause feelings:

  • • The film was interesting.
    • The big dog was very frightening.
    • He was a fascinating man.

• -ed adjectives have a passive meaning. They describe people or animals because people and animals can experience or receive feelings:

  • I was interested in the film. (I felt interested because of the film.)
  • My dog was frightened by the noise. (The dog felt fear.)
  • I was frightened of the big dog

Important: We do not normally use -ed adjectives for objects or things, because they cannot feel emotions.

Quick rule:
-ing → describes cause (active meaning)
-ed → describes feeling (passive meaning; people/animals only)

When learning the -ed adjectives it is important to also learn which prepositions they are commonly used with, e.g. interested in, frightened of & frightened by (frightened of refers to a more permanent state, e.g. I’m frightened of spiders,  whereas frightened by refers to a specific incident, e.g I was frightened by a big black spider in the shower this morning). Becuse the -ed adjectives are passive in nature, the most frequent preposition is by. If there is no object to the adjective, we don’t need a preposition. Compare: I was frightened of the dog & There was a big dog, so I was frightened.

The -ing adjectives do not need prepositions and frequently describe a noun: The film was interesting  – It was an interesting film