Welcome to two of the most difficult sounds for many ESL learners. The first thing that many learners are surprised to learn is that “th” can actually make two sounds. The difference is whether or not you are using your voice. This is called “voicing.”
/θ/ and /ð/ are a consonant pair. /θ/ is voiceless and /ð/ voiced. The top and bottom teeth are brought almost together. The tip of the tongue is placed between the teeth or just behind the teeth – native speakers do this differently, so there is no one right way, as long as you’re making the right sound. The sound comes from the friction of the air escaping between the tongue and the teeth: /θ/ and /ð/. Practice these sounds in a mirror; you should be able to see your tongue between your teeth – not a lot of it, but just a tiny little bit. All right, let’s look at some examples of each of these. I’ll start with /θ/ in word-initial position: thick, thief, thesis, Thursday, thirsty. Now in word-medial position: nothing, lethal, lethargy, mythical, without. And here in word-final position: death, both, paths, tooth, and growth. Okay now let’s look at some words with /ð/. We’ll start in word initial position: them, that, then, this, there. Now in word-medial position: whether, either, or either – you can pronounce it both ways – worthy, mother, leather. And here in word-final position: teeth, soothe, loathe, seethe, writh. Okay, so I’m going to put that there, and I just would like to point something out to you. Okay there’s a list that I would like to show you and that is here. If we look here, we have the voiceless /θ/ and over here we have the voiced /ð/. These words and these changes from from the voiceless to the voiced variant are actually left over from Anglo-Saxon English. In other words, well, sorry, from Anglo-Saxon, which is really before English existed. So if you notice here, we add the the voicing here and here and etc all the way through. What happens is these words, in this list, change from nouns to verbs so bath – so a bath which… I have a bath in my my bathroom. That’s what I have, but what I do, the verb is I bathe. Teeth, we know what teeth are. To teethe, over here, as a verb, is what babies do when their teeth are first growing. “Why is the baby crying all the time?” Well, she’s teething, okay? The teeth are growing in for the first time. So cloth we, we know what cloth is. Clothe is to to put clothes on your body; that’s the verb. Breath is the noun, breathe – this is probably, I’m going to say this is probably the most common of all the ones on this list, even though the, the process is exactly the same in all of them. And then mouth which is what I’m talking with. This is to mouthe which means to when you when you mouthe words you make the actions as though you’re speaking, but you don’t actually say the word. So for example, if I say … I mouthed the word “hello.” I put a set of brackets around this E because it seems to me that that’s becoming much less common. We, we, I hear more and more people mouthing words instead of saying they mouthe words, so probably in another 50 years or so – I’m just making that up, I have no idea when – this will probably be considered completely archaic and that E will probably disappear in all situations. Okay, now there are no minimal pairs here, and so what I have done is I have substituted a common problem that people have, which is /θ/ for /t/. Now, English ears hear the difference, so it’s important that you be able to hear the difference as well, both when you’re listening and when you’re speaking. I’m going to say a word from either one side or the other, and I want you to listen and to decide which word it is that I say. After I’m finished, I will give you the answers. Let’s begin: boat, fort, root, tank, theme, tick, torn, thrash, drill, through. And there’s the answers; those are the words that I just said. How did you do? Okay, thank you very much for your time and attention, and if you’d like some more practice look below.