the sentence--marsha speak excellent german should german be capitlized
Yes. Marsha should also be capitalized. Be sure to worry about subject-verb agreement as well.
The correctly written sentence is this:
Marsha speaks excellent German.
yes
To determine whether "german" should be capitalized in the sentence "Marsha speaks excellent German," you need to consider the rules of capitalization.
In general, languages are not capitalized unless they are used in a title or at the beginning of a sentence. However, there is an exception when referring to nationality or ethnicity, in which case the language can be capitalized.
In this sentence, since "German" is referring to the German language, it should be capitalized. Therefore, the correct capitalization would be "Marsha speaks excellent German."