acostarse vs tumbarse

Question

"La diosa Venus está tumbada sobre una cama mirándose en un espejo, al mismo tiempo que su hijo Cupido, dios del amor sensual, lo sostiene."Instead of está tumbada, I wrote está acostada. I've seen tumbarse used more in literature, but are there any others differences between these two that determined your choice in this instance? Likewise with al mismo tiempo que, I wrote mientras instead.These 2 were not given as alternative answersSaludos a todos

Answer

Hola Graemetumbada and acostada are synonyms and they are both OK to use in this sentence. The same goes to "mientras" as an alternative to "al mismo tiempo que". But sometimes we give the precise word to use in the hint (which is what we did in these two sentences) to reduce the scope.SaludosInma

Answer

Thanks ImnaI'm particularly interested as to why tumbada was chosen in this instance. Is it that there is some subtle difference between tumbarse and acostarse - perhaps something only a native speaker would appreciate - that makes it more appropriate in this case?

Answer

Hola Graeme
we tend to use tumbarse when you just lie down and acostarse with the same meaning but normally implying that you are going to sleep. 
For example, to say "She is lying on the sofa, watching TV" we'd say:
Está tumbada en el sofá, viendo la tele.
To say "she lied on the sofa [with the intention of going to sleep]" we then tend to use:

Se acostó en el sofá.

With the latter, we understand that she lied on the sofa with this intention. 
If we want to say "They are lying on their towels at the beach" we wouldn't use "acostados" here because it would sound as if they were sleeping, but what we mean is they are on their towels sunbathing, or chatting, ... so we'd say:
Están tumbados en las toallas en la playa.
So, in any situation where the lying down doesn't indicate sleeping or an intention to sleep we'd use tumbarse/estar tumbado. 
Saludos
Inma

Answer

Genial! Muchísimas gracias Inma