I just saw that "I am waiting for you" translated as "eu estou esperando por você". Here we have "I am waiting for my mother" translated as "eu estou esperando minha mãe". Why is "por" used in the first instance, but not in the second?
You can choose whether or not use "por", but when we have possessive after 'esperar' we usually omit "por". "Estou esperando você" is also correct.
When do you use por and para
You pretty much have to look up a big list of situational rules and just memorize it.
The EP way of saying it: "Eu estou a esperar minha mãe." should be accepted but it's not
EU-PT - a minha mãe / pela minha mãe
It could also be interesting to explain the differences between BP and EP. Why hiding EP in the lessons and tips?
Please could Duolingo go through this entire section and make sure that a + infinitive is accepted in all cases
Eu estou a esperar a minha mãe ???