"The boy is eating an apple."
Translation:La knabo manĝas pomon.
I just did a quick look through wiktionary and a few other resources, and manĝanta seems to be the active participle in the current tense for a single person. So, from what I've gathered from that and from https://en.glosbe.com/eo/en/man%C4%9Das, it seems like manĝas is more for the word eat as a whole, whereas manĝanta is for the action of eating, so an example would be "mi manĝas" means I eat, whereas it seems like the more correct way of saying "I am eating" would be "mi estas manĝanta."
Ah so LibraMonkey had 2 spelling mistakes for "manĝanta"
"manĝanta" = eating, because "-ant-" = "-ing".
The difference between manĝas & manĝanta is:
The difference between I eat and I am eating, I think?
If I am correctly understanding it:
"La knabo manĝas pomon." = The boy eats an apple
"La knabo estas manĝanta pomon." = The boy is eating an apple
manĝata would actually be "being eaten" - but that's a different lesson (I presume you typod manĝanta)
Remember, -a is an adjective; -anta is the active present participle (The -ing form, as an adjective), so the second sentence should be "estas manĝanta".
In Esperanto, unlike English, the simple form is more common.