You know what the sea is, but do you know any phrases with sea?
If you're at sea, you feel confused and maybe a bit lost.
I studied so hard, I don't know how I failed.
I'm completely at sea.
If your relationship has ended or someone you like is no longer single,
you might say there are plenty more fish in the sea.
There are lots of other people you could have a relationship with.
I know it's hard breaking up, but there are plenty more fish in the sea.
If you look out at a sea of something, it means you can see lots of things in front of you.
For example, when it rains, London turns into a sea of umbrellas.
And if you go to sea, you set out on a voyage.
You can't go to sea in this weather.
There's a huge storm coming.