"He tells her it is impossible."
Translation:Ele diz a ela que é impossível.
In the English sentence, you can choose to use 'that' or not. In portuguese that doesnt happen. You cant omit 'que'.
Ooops, sorry. Here you'll find additional information: http://www.learningportuguese.co.uk/language/object-pronouns.html
Que beleza! That is one mighty useful www site, yet again thanks Paulenrique...
I wrote: "Ele lhe diz que é impossível." It was marked wrong because they had "dizque" as one word. I assume this is their mistake?
I dont know if you asked about this particular sentence or if your sentence could translate Dullingo's original one. About the sentence you quoted, it's right (Congrats), but it doesn't match Duo's sentence ;)
Dizer is a verb that requires preposition. You can't ise o/a
See the comments and links above =)