You have to know that the Hungarian course uses recorded audio, not computer generated voice. All samples must have been recorded with a paid contributor and in certain cases this may be the reason. If you find a sentence where the audio is missing and it would be crucial, please do report it! "Audio doesn't sound right" is a good way, but if you have an option to give detailed non-template message, that is useful, too. And though I wrote about expenses, don't let you detained to ask audio for those sentences that you need them. Contributors will decide whether they could manage it or not ;)
The Hungarian a is the definite article. That means in the vast majority of cases that it should be translated as "the" in English. The main exception is if you talk about general concepts, where English usually doesn't use articles: "Bees are yellow and black" - "A méh sárga és fekete."