"My baby plays with the children."
Translation:Mein Baby spielt mit den Kindern.
After the preposition "mit", you have to use the dative case. In the dative plural, all nouns add an "-n" or "-en". The only exception are nouns whose nominative plural already ends in "-n" (e.g. Frauen) and nouns whose nominative plural ends in "-s" (e.g. Autos).
"die Kinder" (the children, nominative plural) becomes "mit den Kindern" (with the children, dative plural)
Thank you. your explanation of the "n" is clear and easy to understand. Some guy on another comment session made it sound like rocket science.
Isn't Kind same as child, and isn't child same as baby? Granted this is semantics, but just curious.