Before, the alphabet was arranged from 'a to z' by foreign dictionaries, it included two letter sounds. The letters are like two letter sounds in English. 'Ch' in mechanic, or Christmas are good examples. In Viet characters the 'j'(jeh) sound has an equal (sound) that is written as 'tr'(jeh). Letters like 'Tr' used to be in every dictionary's order right in between the other alphabet letters. Another sound is 'ph'. 'Ph' is very famous - it's used in 'phở' the most famous Vietnamese soup in the world. 'Ph' is an 'f' sound, just like in English - 'phone'. 