Ok I completely misunderstood this and thought it meant the bird ate its children!
I did too. I'm really struggling with -ig and -iĝ. Does anyone have any resources I can read that might explain it in a different way?
-ig refers to something other than the subject of the sentence. -iĝ refers to the subject.
I don't think there's a much better way to explain it than Duolingo does. It's not complicated, but its meaning can be pretty variable. In this case, you might think that "manĝigis" means "caused the object to be eaten", but it actually means "caused the object to be fed". As far as I can tell this is specific to that verb and not a function of the way -ig/-iĝ works in general.
So, the "I said I'd feed you. I didn't say who to" pun doesn't work in Esperanto?
"The bird began to eat its offspring " DID seem like an odd sentence....
The suffix -ig- is used to describe an action that makes do, or makes be. For example, manĝi = to eat, manĝigi = to feed (make eat). Another example would be esti = to be, estigi = to create, make, bring into being. It can also be used to turn intransitive verbs into transitive verbs. For example, bruli = to burn (be burning) and bruligi = to burn (something). It can be a verb on it's own, igi.
The suffix -iĝ- is used to describe a becoming. For example, ruĝa = red, ruĝiĝi = to blush (become red). It can also be used to describe a change in state. For example, stari = to stand (be standing), stariĝi = to stand up (become standing). Lastly (as a suffix), it can be used to turn a transitive verb into an intransitive one. For example, rompi = to break (something), rompiĝi = to break (become broken). Similiarly to igi, it can also be a verb on it's own, iĝi.
I hope everything is clear now :)
"to feed" is not completely equal to "to make sb. eat" in English though. So in order to convey the meaning of "make eat", is it correct to say "igi manĝi" in Esperanto?
Dankon por cxi tiu. Gxi clarigxas la ideon por mi.
Thank you for this. It clarifies the concept for me. (Though I feel like I'll be coming back to this explanation several times, as these to suffixes are soo similar that I'll mix them up several times).
Please don't consider this usage to be good Esperanto. As a lot of you have noticed, it is really confusing.
It's allowable, not strictly wrong, and parallels other languages (including English), but the normal way to say "feed one's children" is "manĝigis al siaj idoj."
More generally, the default meaning of taking a transitive verb (like fari) and adding igi (->farigi) is "igi farata." If you want to say "igi faranta," well, you could say that - la birdo igis siajn idojn manĝataj - or just use al.
Please just use al.
The details are in PAG 119(C).