Vowel Teams: Diphthongs (oi, oy)

Free sample questions, a clear explanation, and 5 practice skills with an AI tutor that guides without giving the answer away.

Ahoy, Mates! Let's Find the /oi/ Sound!

Have you ever pointed at something super exciting and said, "Oiii! Look at that!"? That's the sound we're going to explore today! It’s a bouncy, joyful sound, and two special vowel teams work together to make it: oi and oy.

Think of 'oi' and 'oy' as best friends who sound exactly alike. But they have a favorite spot to stand in a word! One friend is a little shy, and the other loves to be the star at the end.

Meet 'oi': The Middle Friend

The vowel team 'oi' is a bit shy. It likes to be tucked right in the middle of a word, with other letters on both sides. When you see 'o' and 'i' together in the middle of a word, they join forces to say /oi/!

Let's look at some 'oi' words:

coin: I found a shiny coin on the ground.
soil: We planted flowers in the dark soil.
point: Can you point to the big, red ball?

Meet 'oy': The End Friend

The vowel team 'oy' is the opposite! It's outgoing and loves to be at the very end of a word. When you see 'o' and 'y' together, they shout /oi/ with joy!

Here are some 'oy' words:

toy: The boy got a new toy for his birthday.
joy: His face was full of joy!
boy: That boy is a good friend.

⭐ Super Speller Tip! ⭐

How do you remember which one to use? It's easy!

Use 'oi' in the middle of a word.
Use 'oy' at the end of a word, with joy!

Sound Showdown!

You've learned about the /ow/ sound in cloud and cow. Now you know the /oi/ sound in coin and toy. Which sound do you think is more fun or interesting?

Write a short paragraph to persuade your friend. Try to use words with all four vowel teams (ou, ow, oi, oy) to make your argument strong! You can start like this:

"I think the /oi/ sound is more interesting than the /ow/ sound. The /oi/ sound brings me joy, like when I find a shiny coin. The /ow/ sound makes me want to shout, but the /oi/ sound is the best choice!"

Sample questions

1. Which word has the /oi/ sound like in "coin"?

○ cat

○ boat

✓ boil

○ book

Answer: boil — Listen for the special sound in the middle of the word.

2. Which letters complete the word: j___n (to put together)?

○ oa

○ ou

○ oo

✓ oi

Answer: oi — What sound do you hear in 'join'?

3. Which word has the 'oi' sound?

✓ point

○ boy

○ cow

○ car

Answer: point — Say the words and listen for the /oi/ sound.

Skills in this topic

Identify the vowel team 'oi' and its /oi/ sound (e.g., coin, boil, join).
Decode words containing the 'oi' vowel team.
Identify the vowel team 'oy' and its /oi/ sound (e.g., toy, joy, boy).
Decode words containing the 'oy' vowel team.
Write a persuasive paragraph arguing which sound ('ow' or 'oi') is more interesting, using words with 'ou', 'ow', 'oi', and 'oy' to support the argument.

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