So, when people do not pronounce TH correctly, what sound do they make instead?
When TH is voiceless (voice is off), common substitutions are T or S, and sometimes F.
When TH is voiced, the most common substitutions are D and Z (or occasionally V).
This can lead to some funny (or perhaps embarrassing) mix-ups. For example, I sometimes hear students say “taught” when they are trying to say “thought” or they say “mouse” when they want to say “mouth”!
Some other possible mix-ups would be:
“thought” might sound like: “taught” “sought” or “fought”
“death” –> “debt” or “deaf”
“thank” –> “tank” or “sank”
“three” –> “tree” or “free”
“think” –> “sink”
“thing” –> “sing”
“fourth” –> “fort” or “force”
“math” –> “mat” or “mass”
“both” –> “boat”
“faith” –> “fate” or “face”
“truth” –> “truce”
“author” –> “otter” or “offer”
“thin” –> “tin” “sin” or “fin”
“those” –> “doze”
“worthy” –> “wordy”
“father” –> “fodder”
“mother” –> “mutter”
“they” –> “day”
“other” –> “udder” (or “utter”)
“either” –> “eater”
You could end up with a funny meaning if you switch some of those words around!
Since the TH sounds in English are used very frequently (and because it is not difficult for the tongue to produce) it would be worth the effort to train yourself to say them right. So, go ahead! Don’t be afraid of TH!
NOTE: there are a few words in which the TH does not make the usual sound. For example, in the name “Thomas”, the TH is actually pronounced as a T sound. Another example is a word like “foothold” which has an accidental TH: the T of the word “foot” happens to be next to the H of the word “hold” but they keep their separate sounds.
PronunciationCoach 