harrymick said:
Thank you very much.
I really want to know, why you created these rules , but you didn’t stand to (should I use 'abide by' instead of 'stand to')it?
How can I do?
You're welcome, and 'abide' is a good word. :-D
The rules were created by speakers. They are the result of natural processes, and they are found in all human languages. For example, in our example (1) below the symbol <th> is pronounced as a voiced sound, as
th in
that, and it's pronounced that way because of where it sits in the array of sounds.
(1) clo
thes [klo:]
th[z] (
th as in
that)
th occurs between two vowels, -o..e
-, and since vowels are voiced sounds, or rather they require that you vibrate your vocal folds, it's easier to pronouce three voiced sounds in a row than it is to pronounce voiced [o], then stop and pronounce voiceless <th>, then stop and pronounce voiced [e]. So you see, it's easier if all three sounds in that row are voiced. And that's why <th> is pronounced as
th in
that, rather than
th in
think. The process by which a voiceless sound is pronounced as a voiced sound is called
Voicing, and it's a result of our human anatomy. That is, if you're human, then you're language will have examples of Voicing. ;-)
As for why some speakers pronounce <th> as [l], well, that involves two other process: some speakers use
Assimilation and other speakers use
Disassimilation.
(2a) c
lo
thes [k
lo:
lz] Assimilation
(2b) clo
thes [klo:
lz] Disassimilation
The process in (2) could be either
Assimilation (to make sounds the same: l...th => l...l) or
Disassimilation (to make sounds different: thz => lz).
Assimilation
The speaker, upon pronouncing the first <l> carries that sound over to the next consonant <th>, giving [k
lo:
lz]. Speakers do it because it's more efficient: It's easier on the lips, tongue, and other articulators, and so the speaker doesn't have to spend much energy on forming two sounds, when one sound, [l], will do.
Assimilation is found in all human languages, even yours.
Disassimilation
Since
th and [z] are very similar sounds, they are difficult to pronounce one after the other, so the speaker changes <th> to [l], to make pronunciation easier. :-D