"My basket is under the table."
Translation:Mijn mand is onder de tafel.
Zitten is used a bit differently than English to sit, and less for positions of things. if I'm not mistaken there are only 3 common usages for zitten:
- people, animals, humanoids (robots, dolls, etc.) in a sitting position
- things that are inside other things er zitten 3 boeken in de mand (there are 3 books in the basket), er zitten 100 jaren in een eeuw (there are 100 years in a century)
- a condition of somebody ik zit lekker in m'n vel (lit. I'm sitting nice in my skin, meaning you're happy/in good spirits)
"De" is used in front of singular nouns of common gender (de tafel, de mens) and plural nouns of both genders (de mensen, de jaren, de dieren).
"Het" is used in front of singular nouns of neuter gender (het jaar, het dier).
Make sure to read the notes accompanying each lesson - they explain the grammatical concepts. See also dutchgrammar.com