freundlichen
freundlichen is an inflected form of the German adjective freundlich, meaning "friendly" or "kind." It is used when the adjective directly modifies a noun (attributive position) and must agree with the noun’s case, gender, and number. The ending -en appears in several common patterns, especially with definite articles and in the dative case.
In plural nouns with a definite determiner, the form appears as freundlichen: Die freundlichen Lehrkräfte erklären
A notable, fixed usage is the closing formula Mit freundlichen Grüßen, which uses the dative plural form
Predicative use of the adjective (after a linking verb like sein) does not take the -en ending:
Etymology and relation to other forms: freundlichen derives from freundlich, whose root freund- comes from the