"It is easy to forget."

Translation: Estas facile forgesi.

[FredCapp]

Finally, I have found the motto to place on my family arms. Facilas forgesi!

[billybolton]

not estas facili forgesi?

[mizinamo]

Why would there be an infinitive ending on "facili"?

"It is to be easy to forget"?

[HWF10]

What about "forgesi facilas"?

[mizinamo]

Is also a possible wording.

[HWF10]

Duo didn't accept it... :/

[mizinamo]

That doesn't surprise me - course maintainers couldn't add all possible permutations of every sentence that Esperanto allows.

Generally, on Duolingo, it's best not to turn adjectives into verbs too much or to use less common word orders.

You can report it if you wish but I'd recommend modifying your language instead :)

[RichDuke]

What about, "Ĝi estas facila forgesi". Would that also be correct?

[mizinamo]

No, because the subject is forgesi -- you don't need an additional dummy subject ĝi, nor can you have one.