This is the 13232nd most frequent German word.
aufmerksamen
"Attentive" or "observant."
Here, 'aufmerksamen' is the adjective describing 'Zuhörer' (listeners). It's in the accusative plural form matching the definite article 'die'. This illustrates its descriptive use in a sentence.
Die aufmerksamen Zuhörer stellten viele Fragen.
The attentive listeners asked many questions.
In this sentence, 'aufmerksamen' modifies 'Blick' (eye or glance) and is in the accusative singular form due to the possessive 'ein'.
Er hat ein aufmerksamen Blick für Details im Bild.
He has an attentive eye for details in the picture.
Here 'aufmerksamen' describes 'Bemerkungen' (comments) in the accusative plural, demonstrating the attributive role of the adjective with plural meanings.