Rules for Words Ending in 'O'

What is the general rule for forming plurals of words ending in 'O'?

• Always add 'ES'

• Always add 'S'

• Usually add 'S', sometimes 'ES'

• Add 'IES'

Which of the following words takes 'ES' in its plural form?

• Photo

• Radio

• Piano

• Domino

Which word does not follow the 'ES' rule for plurals?

• Photo

• Echo

• Hero

• Tomato

What is a common exception to the rule of adding 'S' to words ending in 'O'?

• Words that are compound nouns

• Words borrowed from other languages

• Words related to music

• Words that are abbreviations

Which of the following words correctly follows the pluralization rule by adding 'S'?

• Potato

• Echo

• Piano

• Hero