Spanish Preposition: En
Translation: On, in, at
You can use ‘en’ as a wild card when you are in a hurry or just don’t remember the exact preposition to use when something is «on», «in» or «at» something.
Foreigners can take advantage of ‘en’ being acceptable as a substitute for ‘encima’ [on], ‘dentro’ [in] or even the adverb ‘ubicado’ [at]. English is clearly mucho stricter when it comes to these prepositions.
En la caja
In the box