"Das" (with one 's') is one form of the definite article ("the" in English). "Dass" (or "Daß" using the double 's' of German script) is "that," as in "I know that this is true."
English: "the key word" is German: "das Kennwort", or "das Schlagwort", or "das Schlüsselwort".
The German word for girl is (das) Mädchenor, more regionally, (das) Mädel.
The German word for chicken is (das) Huhn or (das) Hühnchen.
The German word is Reisen. traveling= das Reisen
The German word for book is (das) Buch.
The German word for shop is (das) Geschäft.
The word for pork in German is (das) Schweinefleisch.
The German word for "gift/present" is das Geschenk. This should not be confused with das Gift, which means "poison."
das Problem
das Restaurant
das Schlafzimmer
das Blatt