Expressing Quantities
Have you noticed that in German the word “of” doesn't occur in certain expressions that require it in English? Where we say “a cup of coffee,” German does without the preposition of: eine Tasse Kaffee. There are many examples of this kind of expression. Listen to your CD for the German pronunciation.
Did you notice that the feminine nouns above changed to the plural with the numbers acht and zwei? You say eine Tasse Kaffee and eine Kanne Wasser, but with numbers larger than one, you use the plural: acht Tassen Kaffee and zwei Kannen Wasser. Masculine and neuter nouns do not change to the plural in this instance: ein Glas Bier, zwei Glas Bier.

