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θ
In English, th spells Earth, path, think, which is the IPA sound θ.
However, th also spells this, that, them, which is the IPA sound ð.
Click here to read an article about pronouncing th.
Words with a θ sound
three, thirteen, thirty, thanks, thing, think, thought, thorn, theta, therapy, thief, theatre, thousand
Earth, path, north, south, mouth, month, mathematics, health, strength, youth, truth
Words ending with θ + s
cloths, moths, months, maths, youth's, Earth's
Compare θ and ð
and two examples where one is the noun, and the other is the verb: