The definition of essential is completely necessary or part of the basic nature of something. An example of essential is dedicated study skills to become valedictorian. An example of essential is innate intelligence. Containing, or having the properties of, a concentrated extract of a plant, drug, food, etc.

How do you know if a phrase is essential or nonessential?

An essential clause is not set off by commas or other internal punctuation marks, such as dashes or parentheses, with the understanding that it is a necessary part of the sentence. Conversely, a nonessential clause is set off by punctuation that visually marks it as separate from the main part of the sentence.

What are non-essential words?

Nonessential words and phrases are elements of a sentence which do not contain information essential to the meaning of the sentence as a whole. For example: Jan, the second of three children, always feels left out.