...ok so I'm fed up with everyone saying that Esperanto is just like Castilian Spanish.  It's not, and if it were, how come my Esperanto is tolerably good, while Spanish is my lamentable fourth language?!  Apart from the occasional 'o' these languages are entirely dissimilar with stodgings of false friends.  Here are just a few:

feo; fairy (Esp) ugly (cast)

mesa; adj relating to catholic service (Esp) table (cast)

Barato; India (Esp) cheap (cast)

nana; adj relating to dwarves (Esp) lullaby (cast)

piso; urine (Esp) floor/ room (cast)

rato; rat (Esp) moment (cast)

subiri; to go down (Esp) subir = to go up (cast)

rabo; robbery (Esp) tail (cast)

False phonyms:

coro; koro = heart (Esp) choir (cast)

cola; kolo = neck, kola = adj pertaining to neck (Esp) tail (cast)

capa; kapa = adj pertaining to head (Esp) layer/ coating (cast)

Of course there are synonyms too, but in Esperanto verbs do not conjugate, there are no genders and no subjunctives and certainly no future or imperfect subjunctives!