Voiced TH vs D

they vs day: hear and say the difference

they and day are identical except for one sound: they has the voiced th, /ð/, and day has the d sound, /d/. D taps the ridge and blocks the air for a moment; voiced TH puts the tongue on the teeth and keeps a soft buzz running without ever closing.

Listen

The two words

they

/ðeɪ/

the voiced th

day

/deɪ/

the d sound
Articulation

The difference

What actually changes

D taps the ridge and blocks the air for a moment; voiced TH puts the tongue on the teeth and keeps a soft buzz running without ever closing.

they — /ð/

In the mouth
Lips
Relaxed, slightly apart.
Tongue
Tip touching the back or edge of the top front teeth.
Jaw
Slightly open.
Tongue and lips

day — /d/

In the mouth
Lips
Neutral, slightly apart.
Tongue
Tip on the ridge behind the top teeth, sides sealed.
Jaw
Slightly open.
Tongue and lips
In context

Each word in a sentence

  • they

    They arrived before us.

  • day

    What a beautiful day.

Who merges this

Why this pair is hard

Hindi, Urdu, Bengali, Gujarati, Cantonese, Korean, Thai and Vietnamese substitute d, which turns 'they' into 'day'. Spanish already makes this exact sound between vowels in 'nada', so those speakers have it — they just have to use it at the start of a word.

Questions

Straight answers

What is the difference between "they" and "day"?

One sound. they is /ðeɪ/ and day is /deɪ/ — everything else in the two words is identical, so that single contrast carries the whole meaning. D taps the ridge and blocks the air for a moment; voiced TH puts the tongue on the teeth and keeps a soft buzz running without ever closing.

Why do I say "they" and "day" the same way?

Hindi, Urdu, Bengali, Gujarati, Cantonese, Korean, Thai and Vietnamese substitute d, which turns 'they' into 'day'. Spanish already makes this exact sound between vowels in 'nada', so those speakers have it — they just have to use it at the start of a word.

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 "they" and "day" 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.