As one of the speaker in a school debate, write a speech for or against the motion the use of plastic and plastic related containers should be banned in the country

Betray, destroy, and obey do not need to be changed to add the suffix -ed, because the "y" at the end of each word is preceded by a vowel  (so  they would be spelled  "betrayed," "destroyed," and "obeyed").

but hurry is different; it has to  be spelled "hurried" because the "y" at the end of "hurry" is preceded by a consonant.

Yes i do. i hate my life. it sucks : /