"He always speaks in an interesting way."

Translation: On zawsze mówi ciekawie.

[madvomon]

I was marked wrong for 'Zawsze on mówi ciekawie' - a correct answer is listed as 'zawsze mówi ciekawie' - do you leave the subject out in this case?

[lunaexoriens]

It is about the word order. If you want to put "on", do it in the beginning of the sentence. "Zawsze on" sounds unnatural.

[Andrew.Broz]

Another word order question: does "On zawsze ciekawie mówi" sound natural?

[Jellei]

It sounds even better to my ears. Added now.

[Andrew.Broz]

Thanks!

[IvesAB]

Is it because this way we avoid having the adverb at the end?

[Jellei]

Yes!

[IvesAB]

Great, thank you.

[zagadka314]

Why doesn't "ciekawy sposób" change to another cause because it is "w ciekawy sposób"?

[Jellei]

I think the answer it's that it's a fixed construction.

Also, technically it's not that something is literally "in" (inside) 'an interesting way'.