1. Can language-specific characters (umlauts, accents and so on) be displayed and entered?

Können sprachspezifische Zeichen (Umlaute, Akzentzeichen usw.) angezeigt und eingegeben werden?

2. An umlaut should be distinguished from a change in vowel indicating a difference in grammatic function, called an ablaut , as in sing/sang/sung. Ablaut originated in the Proto-Indo-European language, whereas umlaut originated later, in Proto-Germanic .

Umlaute werden gegenüber dem dazugehörigen Vokal mit spitzerem Mund, bzw weiter vorne im Mund gebildet.

3. We must distinguish it clearly from other forms of gradation which developed later, such as Germanic umlaut (man/men, goose/geese, long/length, think/thought) or the results of English word-stress patterns (man/woman, photograph/photography). Confusingly, in some contexts, the terms 'ablaut', 'vowel gradation', 'apophony' and 'vowel alternation' may be heard used synonymously, especially in synchronic comparisons, but historical linguists prefer to keep 'ablaut' for the specific Indo-European phenomenon, which is the meaning intended by the linguists who first coined the word.

Ein schwaches Verb ist z.B. loben, der Stammvokal ändert sich bei der Vergangenheitsbildung nicht: loben, lobte, gelobt.