Dear German learners,
In the past days I was asked the same question by my students several times: "but what is the difference between “antworten” and “beantworten?”. As many of you might have the same question, I decided to bring this topic up in the community forum. 
So, when do we use “antworten” and when “beantworten” instead? Indeed, in English, both verbs just mean “to answer”. The difference lies in the grammar…
antworten
- Without preposition the verb asks for DATIVE (WEM antworten wir?). Therefore, after the verb we need a person, and not a thing.
Eg. Laura antwortet DEM Lehrer. - If we want to use antworten with a thing we need a preposition, eg. AUF, which asks for accusative.
Eg. Laura antwortet AUF DEN Brief. - In German we can also say how we answer. In this case we also need a preposition, eg. MIT, which again asks for accusative.
Eg. Laura antwortet MIT EINEM Nicken (head nodding).
beantworten
- The verb asks for ACCUSATIVE (WAS beantworten wir?).
- Here, the “be-” gives us the option to replace the preposition AUF in the way that we can make the sentence without preposition, even if we want to use the verb with a thing.
Eg. Laura beantwortet DEN Brief.
I tried to keep the explanation as simple as possible and I hope that it helps some of you to better understand these two verbs… 
Keep up studying
Sunny greetings from Egypt,
Aline
Thank you for your effort 
