Incorrect spelling, explanation: intrested may seem correct because of the pronunciation, but the spelling is different. This word’s etymology comes from the Latin interesse, a merge of two words – inter and esse. As you can see, the letter -e is present in the original spelling. That’s why the correct form is interested.

Correct spelling, explanation: when deriving a word, one must remember to look at its root. In this case, it is the verb interest, not intrest. To form an adjective, adding -ed or -d to the end of the root is necessary. The English word interest originates from the Latin language (interesse). The vowel -e remained, so intrested is incorrect, and interested is the only correct spelling.

Definition of interested:
adjective, state of being curious or concern about something or someone
Tell me more, I’m really interested in this story.
The interested man always shows you attention.

Incorrect spelling

Incorrect spelling

Incorrect spelling