boy vs buy: hear and say the difference
boy and buy are identical except for one sound: boy has the oy sound, /ɔɪ/, and buy has the long i, /aɪ/. Both glide up to 'ee'; OY starts with the lips firmly rounded and the tongue back, long I starts unrounded with the jaw wide open.
The two words
The difference
What actually changes
Both glide up to 'ee'; OY starts with the lips firmly rounded and the tongue back, long I starts unrounded with the jaw wide open.boy — /ɔɪ/
- Lips
- Start firmly rounded, then spread.
- Tongue
- Starts back and mid-low, glides up and forward.
- Jaw
- Starts open, closes through the glide.
buy — /aɪ/
- Lips
- Start open and unrounded, then spread.
- Tongue
- Starts low and central, glides up to the front.
- Jaw
- Starts wide open, closes as the glide finishes.
Each word in a sentence
boy
The boy waved from the gate.
buy
Buy two and save a pound.
Why this pair is hard
Spanish, Italian, German, Hindi and Urdu have both sequences, so the lip rounding at the start is the thing to hold. French, Turkish, Mandarin and Arabic assemble one or both from separate vowels, which blurs the difference.
Straight answers
What is the difference between "boy" and "buy"?
One sound. boy is /bɔɪ/ and buy is /baɪ/ — everything else in the two words is identical, so that single contrast carries the whole meaning. Both glide up to 'ee'; OY starts with the lips firmly rounded and the tongue back, long I starts unrounded with the jaw wide open.
Why do I say "boy" and "buy" the same way?
Spanish, Italian, German, Hindi and Urdu have both sequences, so the lip rounding at the start is the thing to hold. French, Turkish, Mandarin and Arabic assemble one or both from separate vowels, which blurs the difference.
Should I train my ear or my mouth first?
Your ear. If you cannot reliably hear which word was said, your mouth has no target to aim at, and drilling produces a sound you cannot check. Run the listening test on this page until you are scoring four or five out of five, then record the pair.
Say "boy" and "buy" and see which one you said
One take covers both words: reference mode aligns each sound against its target, so the contrast comes back scored on both sides. Free, private, in your browser.