By default the language of the spell checker in English. You can change it with the following snippet (which allows English and German)

 
function fb_mce_external_languages($initArray){ 
$initArray['spellchecker_languages'] = '+German=de, English=en'; 
 
return $initArray; 
} 
add_filter('tiny_mce_before_init', 'fb_mce_external_languages'); 
Happy
Happy
0 %
Sad
Sad
0 %
Excited
Excited
0 %
Sleepy
Sleepy
0 %
Angry
Angry
0 %
Surprise
Surprise
0 %