Today, an earthquake occurred. Today, an earthquake occurred.

Today, an earthquake occurred. Today, an earthquake occurred.

When you talk about one earthquake, you need "an" or "the" before the noun.

But I doidn't feel scared. But I didn't feel scared.

Use past tense when talking about something in the past.

But I doidn't feel scare.d But I didn't feel scared

Continue with the past tense.

Because earthquakes often occur in Japan. Because earthquakes often occur in Japan.

General statements like this usually use plural.

Bbecause earthquakes often occur in Japan. because earthquakes often occur in Japan.

This can be added to the sentence before it.

I think that getting used to earthquakes is dangerous. I think that getting used to earthquakes is dangerous.

I think that getting used to earthquakes is dangerous. I think that getting used to earthquakes is dangerous.

Add "s" for the plural.

It make mone let one'stheir guard down. It make one let their guard down.

If you want to use the word "one," be consistent

It make me let one'smy guard down. It make me let my guard down.

It's important for the grammar to match the person. For "me" the possessive is "my."

I can't doing some anything when I face a really dangerous situation. I can't do anything when I face a really dangerous situation.

Use "anything" instead of "something" in a negative sentence

I cawon't doing somebe able to do anything when I face really dangerous situation. I won't be able to do anything when I face really dangerous situation.

I am guessing that you are talking about the future. "I won't" uses the future tense = "I will not." "Something" is understandable, but most native speakers would say "anything" in this sentence.

I think that getting used to earthquakes is scarey. I think that getting used to earthquakes is scary.

"Scare" is a verb, "scary" is an adjective

I think that getting used to earthquakes is scarey. I think that getting used to earthquakes is scary.

Today's text used many challengeing expressions. Today's text used many challenging expressions.

"Challenge" is a verb, "challenging" is an adjective (it's very strange, honestly...)

Today's text used many challengeing expressions. Today's text used many challenging expressions.

challenging = hard, difficult (a challenge can be good or bad)

I might have made many mistakes.. I might have made many mistakes..

Use plural after "many"

I might have made many mistake.s. I might have made many mistakes.

Add "s" for the plural. (earthquakes, mistakes, expressions)