Problems with grammer: she was frightened vs she was frightening

[Saj]

hi there

i was asked some questions by my teacher and i dont know how to answer them. she says that for each one i should not give an answer that is predictable but rather explain in terms of the tense that is used in the wrong way.

1) why can you say "she was frightened" and "she was frightening" but not "the film was frightened" * teacher said we should look at verbs ending with ed here and ing
-i dont understand-

2) why do you say "prettier" but not "beautifuler"
* teacher said that we should look at comparitives and superlatives*
-please explain in this context-

3) why cant you say " i have been knowing him for 2 years"
please explain in terms of gramatical errors

[Milanya]

1. Frightened means scared, frightening means scary.
She might be scared (frightened) if somebody or something scare her, she might be scary (frightening) if somebody or something is afraid of her. A film is not a living thing, you cannot scare a film, a film cannot be scared (frightened) but you may be scared by a film, this film is frightening (scary).
2. You can say "more beautiful."
With most two-syllable adjectives, you form the comparative with more and the superlative with most.
3. "Know" is a stative verb and the progressive forms do not occur with stative verbs, they occur only with dynamic verbs.

Grammar is the correct spelling.
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con·text - The part of a text or statement that surrounds a particular word or passage and determines its meaning.

[Gray]

"Means" and "occur" are correct spellings ;)

When exactly we say that it is a typo and not a spelling mistake?
-- a genuine question, not kidding :)
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First lesson - English, not english. I, not i. ~A student of English

[Milanya]