Version: (using KDE KDE 3.5.2)
Installed from: Ubuntu Packages
I know there are other wishlistitems about autodetecting the language and such, but this one is much simpler.
Make it possible to spellcheck with more than one language. OpenOffice.org has this ("spellcheck in all languages").
The most people will use 2 languages, like Dutch and English, but I can also imagine people use Frisian, Dutch and English. Anyhow I think this will be very easy to make. Just make it possible to set more than one language as default.
It's not that easy.
*** Bug 194854 has been marked as a duplicate of this bug. ***
*** Bug 275488 has been marked as a duplicate of this bug. ***
*** This bug has been confirmed by popular vote. ***
Actually, there is a simple workaround: use a combined dictionary that contains words from two languages. It's not that hard to even make one by yourself.