What do you mean "once I reflashed it"? Are you refuring to a master reset? cause you also ask how to flash it, yet you said you flashed it already. And I have no idea how your missing english, because english is in all the FS versions! The only way I even see possible that you have just those languages is that the person you got it from customized the whole thing because those languages don't exist together on any FS. What I suggest you do is look here for a FS for your phone that has the languages that you want. Then download that FS, a MAIN of the same firmware version (normally just the Generic but if your wanting Chinese your going to need to use something like CHINA_MAIN or TAIWAN_MAIN or something like that) you will also need the customization file to go with that as well. this is a pretty good tutorial on how to do it all. Read it all first before you do anything.