As a casual speaker of Esperanto, I’m used to constructions where ”al la X-o” or ”sur la X-on” is replaced by ”-en”:

> 
> Ni iru **aŭten**! (Ni iru al la aŭto.)
> 
> 
> Via poŝtelefono falis **teren**. (Via poŝtelefono falis sur la teron.)
> 
> 
> 

Yes, I know, according to classical analysis, the highlighted words are adverbs (even if they are modified and don’t end ind **-e** as other adverbs).

However, some languages do have an allative case, which expresses movement to(wards) something. An example would be the Basque word *Bilbora*, meaning ”to(wards) Bilb(a)o”.

Would it be possible to re-analyse some **-en** words as allatives rather than adverbs?