Usages of el mar
No puedes nadar aquí porque el mar es más peligroso que el río.
You cannot swim here because the sea is more dangerous than the river.
El océano es menos tranquilo que el mar.
The ocean is less calm than the sea.
Hacía cinco días que yo miraba la inmensidad del mar.
I had been looking at the immensity of the sea for five days.
Elon.io is an online learning platform
We have an entire course teaching Spanish (Latin America) grammar and vocabulary.