S vs Z

sue vs zoo: hear and say the difference

sue and zoo are identical except for one sound: sue has the s sound, /s/, and zoo has the z sound, /z/. Same narrow groove behind the teeth, same hiss position: S is pure air, Z turns the voice on so the hiss becomes a buzz you can feel in your throat.

Listen

The two words

sue

/suː/

the s sound

zoo

/zuː/

the z sound
Articulation

The difference

What actually changes

Same narrow groove behind the teeth, same hiss position: S is pure air, Z turns the voice on so the hiss becomes a buzz you can feel in your throat.

sue — /s/

In the mouth
Lips
Slightly spread, corners back.
Tongue
Tip near — not touching — the ridge, with a narrow groove down the middle.
Jaw
Almost closed; the teeth nearly meet.
Tongue and lips

zoo — /z/

In the mouth
Lips
Slightly spread.
Tongue
Tip near the ridge with a narrow groove — the same shape as S.
Jaw
Almost closed.
Tongue and lips
In context

Each word in a sentence

  • sue

    They threatened to sue the company.

  • zoo

    The zoo closes at five.

Who merges this

Why this pair is hard

Spanish, Tamil and Thai have no z at all, so every plural and every 'is' ends in a hiss. Bengali, Gujarati and Korean replace z with a j sound. German and Russian devoice a final consonant, so 'rise' ends like 'rice'. Mandarin and Cantonese have no final consonants, so the ending disappears rather than changes.

Questions

Straight answers

What is the difference between "sue" and "zoo"?

One sound. sue is /suː/ and zoo is /zuː/ — everything else in the two words is identical, so that single contrast carries the whole meaning. Same narrow groove behind the teeth, same hiss position: S is pure air, Z turns the voice on so the hiss becomes a buzz you can feel in your throat.

Why do I say "sue" and "zoo" the same way?

Spanish, Tamil and Thai have no z at all, so every plural and every 'is' ends in a hiss. Bengali, Gujarati and Korean replace z with a j sound. German and Russian devoice a final consonant, so 'rise' ends like 'rice'. Mandarin and Cantonese have no final consonants, so the ending disappears rather than changes.

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 "sue" and "zoo" 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.