When someone dresses up, they put on special clothes. When you dress up as someone, you put on the sort of clothes that that person wears.
Mr White dressed up as a clown to entertain the children.
If you dress in something, you wear it. If you are dressed in something, you are wearing it.
Paula dressed in black for the funeral.
If you wrap up, you put on warm clothing.
If you're going out, wrap up. It's going to snow.
If you strip off, you remove most or all of your clothes.
John stripped off and dived into the water.
When you lounge around, you spend time in a lazy or relaxed way.
He spent the whole morning lounging around in the garden.
When you look ahead, you talk or think about what will happen in the future.
I'm looking ahead to the party tomorrow night and wondering what I should wear.
When the sky clouds over, it becomes covered with clouds.
It's starting to cloud over and I'm afraid it's going to rain.
When it pours down, it rains very hard.
It's pouring down outside and you'll get soaking wet.
When it brightens up, the weather becomes sunnier.
It'll brighten up soon and then you can go out and play again.
When the sun comes up, it appears in the sky.
The sky starts to get brighter in the east before the sun comes up.
When the sun goes in, it becomes covered by a cloud.
It got much colder when the sun went in.
When the sun comes out, it shines again.
I waited for the sun to come out before I took the picture.
When the sun goes down, it disappears from the sky in the evening.
As the sun went down, the sky turned a beautiful red color.
If something is going on, it is happening.
What is going on in there? Who is making that horrible noise?
If an object warms up, it becomes warmer.
Wait for the oven to warm up before you put the meat in.
If a river, lake or steam dries up, there is no more water in it.
During hot, dry summers this stream dries up.
If a type of plant or animal dies out, there are no more such plants or animals.
People hunted these birds for food, and finally the birds died out.
If you disagree with someone, you believe that they are wrong.
John disagrees with Peter about the best day for the party.
When something cools down, it becomes cooler.
The plates are very hot. Wait for a minute until they have cooled down.
When something freezes over, it becomes covered in ice.
The pond in our garden froze over last winter.