for iOS 5.1 software

Vietnamese
Touch and hold a character to see the available diacritical marks, then slide to choose the one
you want.
You can also type the following key sequences to enter characters with diacritical marks:
aa—â Â (a circumex)
aw—ă Â (a caron)
as—á Â (a acute)
af—à Â (a grave)
ar—ả Â (a question mark)
ax—ã Â (a rising accent)
aj—ạ Â (a drop tone)
dd—đ Â (d dash)
ee—ê Â (e circumex)
oo—ô Â (o circumex)
ow—ơ Â (o hook)
w—ư Â (u hook)
172
Appendix A International Keyboards