The word crowds is a noun and the word crowded in an adjective. You can use the word crowd to describe a group of people or items: "There was a crowd in the store" "There were crowds of people around the singer." When using the word crowds you can replace it with the word group and it would still sound correct. On the other hand, the word crowded is describing a noun. We can say the the store was crowded, the street was crowded, etc. When you use the word crowded the word "to be" or any conjugated variation usually comes first. "It is/was/will be crowded." However, it can also stand alone such as "The crowded mall was very hot." This word always describes the state of a certain place. Hope this helps!

Crowds = plural of crowd. It's a noun. Crowded = taken from the verb form. You can now use it as an adjective. "The streets were crowded everywhere" is the proper sentence.

They were crowding the streets everywhere. There were huge crowds everywhere. There was a huge crowd. Notice I did not use the word, "people". It is understood. If it was something else, then you state that something else explicitly. "There was a crowd of elephants by the watering hole."

I know what it confused me....I used the crowded as verb in the past form. I didn't know that that is adjective and I don't know why I thought about that. :) Many thanks.

Thanks all of you. :)