I was confused by the pronunciation of consonant cluster 'ths' at the end of the word.
For example: the cluster 'ths' in word months, according to ESL teaching videos on Youtube,video for months' pronunciation on youtube can be pronounced as /ths/(which is the pronunciation listed in most of the dictionaries), /ts/ and /s/. As for word baths, I could not find a video explanation by searching internet. But I assume that the word baths should be pronounced as /baths/ or /bas/, but not /bats/(As I couldn't think of any rules for this pronunciation)
I'm not sure whether the above descriptions are correct or not, so please correct me if there are any mistakes or exceptions. Thanks in advance.
Best Answer
You're right that "baths" would not be expected to ever be pronounced with a [t] sound.
It's only possible to have [t] in "months" because of the "n" preceding the "th." When a nasal consonant such as /m/, /n/ or /ŋ/ (the "ng" sound in "sing") precedes a voiceless fricative consonant such as /f/, /s/ or /θ/ (the "th" sound in "thin"), many speakers introduce an epenthetic voiceless plosive. The identity of this plosive depends on which nasal consonant is present: we get [p] after /m/, [t] after /n/, and [k] after /ŋ/.
This means that "month" (most commonly transcribed /mʌnθ/) may be pronounced as [mʌntθ]. Both variants, [mʌnθ] and [mʌntθ], are generally considered to be standard English.
I've never noticed the plural being pronounced as [mʌnts] or [mʌns], but that wouldn't surprise me too much as [mʌntθs] has a rather awkward four-consonant cluster that seems like it would be prone to simplification in a similar way to /siksθs/. This pronunciation is mentioned in another, related question: Do most Americans pronounce 'months' as 'mons', and 'clothes' as 'clos'?
In the word "bath," there is no nasal consonant preceding the /θ/ sound, so you cannot insert an epenthetic [t]. (Speakers of some varieties of English might outright replace the /θ/ in this word with a [t] sound, a phenomenon called "th-stopping", but this is not standard and would not be taught to ESL learners.)
The plural "baths" may be subject to another process however: fricative voicing. In English, words that end in a voiceless fricative sometimes have voiced fricatives in their plural forms. The voiceless fricatives /f/, /s/, /θ/ correspond to the voiced fricatives /v/, /z/, /ð/ respectively.
In cases where the voiceless fricative is voiced, the plural suffix "-s" is also pronounced as a voiced consonant /z/.
For the word "baths," voicing the fricative is optional. So you may hear it pronounced with either /ðz/ or /θs/.
I don't have enough knowledge of phonetics to say if these clusters are ever reduced in fast speech to single consonants [z] or [s]. But I would say your target pronunciation for the word "baths" should end in a cluster of two consonants.