One aspect of language that all languages have in common is constituents. All languages are organized in constituents, allowing more complex units to enter structures where simpler ones are also possible. The following examples in English illustrate constituents (in italics).
She sat down
The smart woman sat down
The tall, smart woman with the bright orange sweater sat down
Constituents can be replaced by other constituents and can be moved if you move the complete constituent. The complete constituent "the tall, smart woman with the bright orange sweater" can be replaced by the pronoun "she." In the examples above, the constituent is the subject of the sentence but it can also be in the predicate of the sentence.
I saw the tall, smart woman with the bright orange sweater
I saw her
Can you find the constituents in the next sentence?
The black and white squirrel that looks like a skunk ran up the tree.