two different fonts in a text box!

So long as you don't need to use both fonts at the same time you can stack the fields on top of each other. Then when you need English, you set 'Native Language' (NL) to hidden & does not print. When you need NL you hide English and unhide the NL version.So long as you don't need to use both fonts at the same time you can stack the fields on top of each other. Then when you need English, you set 'Native Language' (NL) to hidden & does not print. When you need NL you hide English and unhide the NL version.While this does require a bit of programming on your part (as you have to code for the switch) it is fairly straightforward.

Also, you can save some programming headaches if you use a hierarchical naming scheme - that way you just need to hide/un-hide the properties on the top level name.

If you need both fonts in the same box, sorry, cannot be accomplished. It's like cells in Excel - one font/style per cell only.

What about the same font but 2 different sizes on 2 different lines.

You cannot have two fonts in the same text box / field element - even on different lines.

Note: The strict definition of a Font is a typeface (Helvetica, Times, WinDings, etc.) instanciated in a specific style/weight (bold, italics, heavy, etc.) at a specific size (e.g. 10.5pt or 10/12pt).