Serif font would help readability.

[Tom921]

Using a serif font would allow easier distinguishing letters such as "I" and "l"

[kristinemc]

We're working on making it easier to distinguish between those two letters.

[Nekosuki]

I agree. I recently had trouble telling apart "lo" (the) from "Io" (I) in the Italian lessons because of this, so I had to guess which one was which. This is how it went: http://s15.postimage.org/lsg7w988b/image.jpg

[tylrmurphy]

Il mange.

Curse you Helvetica.

[aaronwright987]

I vote for another font too. This is very annoying.