OY vs long I

boil vs bile: hear and say the difference

boil and bile are identical except for one sound: boil has the oy sound, /ɔɪ/, and bile 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.

Listen

The two words

boil

/bɔɪl/

the oy sound

bile

/baɪl/

the long i
Articulation

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.

boil — /ɔɪ/

In the mouth
Lips
Start firmly rounded, then spread.
Tongue
Starts back and mid-low, glides up and forward.
Jaw
Starts open, closes through the glide.
Tongue and lips

bile — //

In the mouth
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.
Tongue and lips
In context

Each word in a sentence

  • boil

    Boil the kettle, please.

  • bile

    The word left a taste of bile.

Who merges this

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.

Questions

Straight answers

What is the difference between "boil" and "bile"?

One sound. boil is /bɔɪl/ and bile is /baɪl/ — 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 "boil" and "bile" 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.

Practise this word

Say "boil" and "bile" 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.