What is a complete subject?

A complete subject is the simple subject plus the words that modify it.

Example: The boy with blue hair is a math genius.

Simple subject: boy
Complete subject: The boy with blue hair

Example:
One of my best friends is going to Vietnam this summer.

Simple subject: One
Complete subject: One of my best friends

Check this site.

http://ace.acadiau.ca/english/grammar/gsubpred.htm

A complete subject is a part of a sentence that includes all the words that describe the main subject of the sentence. It usually consists of a noun or pronoun along with any modifying words. The complete subject provides information about who or what the sentence is about.

A complete subject is a fundamental concept in English grammar. To understand what a complete subject is, we first need to understand what a subject is.

In a sentence, the subject typically tells us who or what is performing the action or being described. It is usually a noun, pronoun, or group of words acting as a noun.

Now, to identify the complete subject, you need to look for all the words that describe or modify the subject in a sentence. The complete subject consists of the simple subject (the main noun or pronoun) along with any modifiers, adjectives, or descriptive words that provide more information about the subject.

To identify the complete subject in a sentence, follow these steps:

1. Find the verb: Identify the action being performed or the state of being.
2. Ask the question: "Who?" or "What?" before the verb.
3. The answer to the question is the simple subject.
4. Identify any words that modify or describe the simple subject. These words, along with the simple subject, form the complete subject.

Let's take an example sentence: "The big, fluffy dog ran across the field."

1. Find the verb: In this case, the verb is "ran."
2. Ask the question: "Who ran?" The answer is "dog."
3. The simple subject is "dog."
4. Identify any modifiers: "The," "big," and "fluffy" are words that modify the simple subject "dog."

Therefore, the complete subject in the given sentence is "The big, fluffy dog."

By following these steps, you can identify the complete subject in any sentence.