Questions & Answers about Marie rêve souvent de la mer.
In French, the verb rêver meaning to dream (about something) normally takes the preposition de:
- rêver de quelque chose = to dream about/of something
Rêver la mer would sound wrong in everyday modern French in this meaning.
Rêver sur la mer would mean to dream on the sea (for example, if you’re sleeping on a boat), which is different.
So to say dream about the sea, you pretty much have to say rêver de la mer.