* Th - This is a single phoneme, representing the "th" sound.
* O - This is a single phoneme, representing the "oh" sound.
* U - This is a single phoneme, representing the "oo" sound (as in "book").
* Gh - This is silent in this word, so it doesn't contribute a phoneme.
Therefore, "though" has 4 phonemes: /θoʊ/.