Vocabulary
The most obvious difference between German and Swiss German is their vocabulary. Many words that are used in German have different equivalents in Swiss German. For example, the German word "Auto" (car) is "Autö" in Swiss German. The German word "Bahnhof" (train station) is "Banhof" in Swiss German.
Grammar
The grammar of German and Swiss German is also different. For example, the German verb "sein" (to be) is conjugated differently in Swiss German. In the present tense, the German verb "sein" is conjugated as "ich bin, du bist, er/sie/es ist, wir sind, ihr seid, sie sind." In Swiss German, the verb "sein" is conjugated as "i bi, du bisch, är/si/es ischt, mir sind, ihr sind, si sind."
Pronunciation
The pronunciation of German and Swiss German is also different. For example, the German "ch" sound is pronounced as a guttural "kh" sound in Swiss German. The German "r" sound is pronounced as a trilled "r" sound in Swiss German.
Mutual intelligibility
Due to the differences in vocabulary, grammar, and pronunciation, German and Swiss German are not mutually intelligible. This means that speakers of German and Swiss German cannot understand each other without learning the other language.