"I pay for the friends."
Translation:Ich bezahle für die Freunde.
Bezahlen can mean to "pay for something / some service" where the "for" is built in. 'Ich bezahlte den Kaffee" = "I paid for the coffee."
But when the object is a person, instead of an object / service, then it means you are paying money to that person.
"Ich bezahle die Freunde" would mean "I am paying the friends" instead of "I am paying FOR the friends.". That's why you need the "für" here.
There is a good explanation of bezahlen and zahlen here: https://german.stackexchange.com/questions/7097/when-to-use-bezahlen-and-when-zahlen
I got another sentence wrong for using "fur" after "bezahlen", now I get this one wrong for not using "fur" after bezahle". I don't understand this at all. What is the problem? Duolingo told me that the "fur" was implied with "bezahlen". The implied "fur" doesn't seem to count now?