"I speak to the heart."
Translation:Ich spreche das Herz an.
in English, 'I speak to the heart' and 'I speak with the heart' are not the same. 'to the heart' is more of an appeal to someone else's emotions. 'with the heart' is speaking from my heart.
Duolingo says that 'ich spreche mit dem Herzen' can translate to either of these meanings. Is 'mit dem Herzen' idiomatic for 'to the heart'? How would you say 'I speak with the heart' or even 'I speak with my heart'?
That is the way it is written in Dative singular (and plural). If you only had the German sentence and were debating whether it was plural or singular, you'd reference the preceding article. Dem = singular, den = plural.
According to canoonet however, both "dem Herz" and "dem Herzen". Additionally, from what I understand (German isn't my first language), Duden says that "dem Herz" is preferable over "dem Herzen". So if both aren't accepted, perhaps flag it next time. If you were just wondering why, I hope this helps and doesn't make it worse!