Hi,

in an older version of texstudio, i could switch the dictionary language from
the menubar. However, in the 2.4 version, I cannot see where I can add this
item to the menu... It was very convenient for people making different
documents in different languages...

Best,

the switch has been move to the lower status bar

The spellchecker also supports more advanced settings like default dictionary,
document specific dictionary and the possibility to define it via meta-tags in
the file.

see section
1.4.1 Configuring the spell checker
in the documentation.