Week 2 on Coursera : Miracles of human language (Introduction of human language)

From what i learned on Week 2 in Coursera is learned anout Phonetics and Phonology. i learned kinds of phonetics patterns, like : /tr/ is OK in the middle of words, however, e.g. in "ashtray", and The consonant cluster /st/ is OK at the beginning, middle or end of words in English.

they taught sound systems has 26 letters made up of consonants and vowels. they give the example such as there are two syllables in wa/ter and three in in/fer/no.

Prof. Marc taught that most of the phonemes like Thus, /water/ has two syllables but four phonemes: w/a/t/er; /inferno/ has three syllables but seven phonemes: i/n/f/e/r/n/o.

And that what i learned in Coursera is to have a meaning of how consonants are made also for Phonology and Phonetics as well.