Звуки th: /θ/ і /ð/

When it matters

The two th sounds are among the most frequent sounds in English. They begin the, this, that, they and there, so you need them in almost every sentence. Neither Ukrainian nor Russian has them, and learners naturally replace them with the nearest familiar sound. Sometimes that only gives an accent, but often it changes the word: think turns into sink, three into tree or free, mouth into mouse. It is worth learning the right tongue position early, before a habit forms.

How it works

The spelling th stands for two different sounds:

• /θ/ is voiceless, as in think /θɪŋk/.
• /ð/ is voiced, as in this /ðɪs/.

For both sounds, put the tip of your tongue lightly against the back of your upper front teeth, or just between the upper and lower teeth. Then push air out through the narrow gap. The tongue does not block the air, as it does for /t/ or /d/; the air keeps flowing, so you can hold the sound for as long as you like. Your lips stay relaxed and do not touch the teeth. That is the difference from /f/ and /v/, where the lower lip touches the upper teeth.

To feel the difference between the two, put your fingers on your throat. For /θ/ there is no vibration, only a stream of air, like a soft /s/. For /ð/ the throat vibrates, as it does for /z/ or /v/. The tongue is in exactly the same place for both.

The spelling does not show which sound a word has, but four patterns cover most words:

• Small grammar words that start with th have /ð/: the, this, that, these, those, they, them, their, there, then, than, though.
• Most other words that start with th have /θ/: think, three, thank, thing, Thursday.
• Between two vowels, th is usually /ð/: mother, father, other, weather, together.
• At the end of a noun or adjective, th is usually /θ/: bath, month, mouth, tooth, both. A verb that ends in -the has /ð/. This gives useful pairs: breath /breθ/ and breathe /briːð/, bath /bɑːθ/ and bathe /beɪð/.

A few words are simply exceptions. Thyme is /taɪm/, with a plain /t/, and with can be /wɪð/ or /wɪθ/; both are correct.

Practice words

Voiceless /θ/:

Word	Sound	Compare with
think	/θɪŋk/	sink /sɪŋk/
three	/θriː/	tree /triː/, free /friː/
thank	/θæŋk/	tank /tæŋk/
thin	/θɪn/	sin /sɪn/, fin /fɪn/
mouth	/maʊθ/	mouse /maʊs/
month	/mʌnθ/
birthday	/ˈbɜːθdeɪ/
Thursday	/ˈθɜːzdeɪ/
nothing	/ˈnʌθɪŋ/

Voiced /ð/:

Word	Sound	Compare with
they	/ðeɪ/	day /deɪ/
then	/ðen/	den /den/
that	/ðæt/
breathe	/briːð/	breeze /briːz/
clothing	/ˈkləʊðɪŋ/	closing /ˈkləʊzɪŋ/
mother	/ˈmʌðə/
weather	/ˈweðə/
together	/təˈɡeðə/

Say each pair slowly, then quickly. Then try a short phrase with several of them: Thank you, I think so. They are over there.

Common mistakes

• ✗ /sæŋk ju/, /aɪ sɪŋk səʊ/
  ✓ /θæŋk ju/, /aɪ θɪŋk səʊ/
  Replacing /θ/ with /s/ is the most common habit, because /s/ is the closest sound in Ukrainian and Russian. For /s/ the tongue stays behind the teeth; for /θ/ it must come forward and touch them.
• ✗ /zɪs/ or /dɪs/ is my brother.
  ✓ /ðɪs/ is my brother.
  A /z/ or /d/ in place of /ð/ is very noticeable, because the, this and that appear in almost every sentence. Keep the voice on, as for /z/, but put the tongue against the teeth.
• ✗ /triː/ or /friː/ tickets, please.
  ✓ /θriː/ tickets, please.
  Here the substitute makes a different word: tree or free. When a number is involved, this matters for real.
• ✗ /teˈɑːtr/, /ˌmætəˈmætɪks/
  ✓ /ˈθɪətə/, /ˌmæθəˈmætɪks/
  Ukrainian and Russian borrowed these Greek words with т: театр, математика, метод, теорія / теория. English kept the th: theatre, mathematics, method /ˈmeθəd/, theory /ˈθɪəri/. American English spells the first word theater.
• ✗ Breath deeply.
  ✓ Breathe deeply.
  The noun breath has a short vowel and /θ/; the verb breathe has a long vowel and /ð/. They are two different words, both in spelling and in sound.

Try it