This is the 14685th most frequent German word.
nachmittags
"In the afternoon."
In this example, 'nachmittags' indicates the preference for engaging in the activity during the timeframe of the afternoon.
Am liebsten spiele ich nachmittags Fußball.
I prefer playing soccer in the afternoons.
In this sentence, 'nachmittags' is used as an adverb and means 'in the afternoons'. It describes when the activity (the walk) happens.
Ich mache nachmittags immer einen Spaziergang.
I always go for a walk in the afternoons.
Here, 'nachmittags' again functions as an adverb, specifying the time of the day when the German lessons take place in the ongoing manner.