My spell check is locked into German. When I type (English) everything is underlined because it is misspelled. I have tried to change the spell check from German to English, but it will not change.
Change the language of the paragraph style(s) used to the language typed.
Because of hierarchic style template organization changing the Standard style is sufficient in most cases.
This is a good idea but will help only when there is no overriding ad hoc formatting applied. Besides, the behavior described by the topic starter implies some problems with the spellcheck setup.