Roger Woodham replies:afraid,scared,frightening,terrifying
afraid / scared / frightened
 
There are differences in use and I shall try to illustrate these. But all these adjectives express roughly the same degree of worry or fear and can therefore be used interchangeably to some extent. Frightened suggests more sudden fear:
 
All small children are afraid of / scared of / frightened of school bullies.
 
Don’t be scared / afraid / frightened. I’m not going to hurt you.
 
All three can be followed by of + -ing clause. Frightened cannot always be followed by of + pronoun or noun:
 
He’s afraid of / scared of / frightened of flying in small planes.
 
He’s a strict teacher. Everyone seems to be afraid of / scared of him.
 
All three can be followed by the to + infinitive pattern:
 
She seemed too scared to swim where there were such big waves.
 
After such an experience she’s afraid to go anywhere near the sea.
 
I was too frightened to jump in at the deep end of the pool.
 
We can be scared by or frightened by something. We cannot use afraid in this way:
 
She was scared by the hooting of the owl.
 
They were frightened / terrified by the gunfire and the breaking of glass.
 
Note that terrified expresses a stronger degree of fear.
 
She’s terrified of / by large dogs and won’t go near them.
 
 
afraid / scared / frightened - position in clause
 
 Note that afraid is one of those adjectives that cannot normally be used before a noun, but instead is used after a verb. Scared and frightened can be used in both positions:
 
He seemed afraid. He appeared frightened.
 
He was, without doubt, a frightened man.
 
 
I’m afraid I / we / he / etc
 
 I’m afraid… is also used in another way, meaning: I regret that I have to tell you that…. It is used to introduce bad news in a gentle or polite way:
 
I’m afraid there’s been an accident at the crossroads. Your son’s been knocked over on his bike.
 
I’m afraid we shan’t be able to come on the skiing trip with you. John’s got to work.
 
He’s done very little work, I’m afraid. He’ll have to repeat the course.
 
 
I’m afraid so. / I’m afraid not.
 
 We can use these forms as short answers to confirm bad news:
 
Will I really have to repeat the course next year? ~ I’m afraid so.
 
Can’t you really come on the skiing trip with us? ~ I’m afraid not.
 
 
frightened / frightening
 
 As a general rule, adjectives ending in -ed are used to describe how people feel. Adjectives ending in -ing describe the things or situations that give rise to these feelings. So, remember, frightened describes how you feel. Frightening describes the things that make you feel frightened:
 
She looked very frightened when I told her she would lose her job.
 
It was one of the most frightening films I had ever seen.
 
It’s frightening to think that they are capable of producing nuclear weapons.
 
 
terrified / terrifying
 
 Similarly, terrified describes you feel. Terrifying describes the things that make you feel terrified. Terrified and terrifying express a higher degree of anxiety or worry than frightened and frightening:
 
I was so much in debt. I was terrified I would lose my job when the restructuring was announced.
 
It was a terrifying experience. I doubt he will ever recover from it.
 
 
scared / scary
 
 Scary is the adjective relating to things or situations; scared the adjective relating to how people feel. Scary and frightening express similar levels of fear or worry:
 
Being alone in a cave with five thousand bats was scary.
 
I felt scared when night fell and I was nowhere near human habitation.