3.what is the preposition in the sentence?

The children sat under the tree.
A. sat
B.children.....
C.under
D.the

Here are some prepositions:

Behind
Under
Across
Above
Within
Among
Beside
On
In
Over
Off
To
At
etc.

Under

Prepositions are about time and location. Think about the word describing time and loation.

#1. Bookmark this so you can find it again and again when you need help with English grammar ~~> http://www.chompchomp.com/terms.htm

#2. Once bookmarked, scroll down and find Preposition. Read and study this webpage.

The preposition in the sentence "The children sat under the tree" is "under".

To determine the preposition in a sentence, you need to identify a word that shows the relationship between other words in the sentence. In this case, the word "under" shows the relationship between "the children" and "the tree".

Prepositions are typically used to indicate location, time, or direction. In this sentence, "under" is indicating the location or position of the children in relation to the tree.