Direct Examples:
* "The cat sat on the mat." Here, "cat" is the subject, and it's clearly functioning as a noun.
* "History is full of surprises." "History" is the subject, acting as a noun representing a specific field of study.
* "Math is my favorite subject." "Math" is the subject, functioning as a noun referring to the subject of mathematics.
More Complex Examples:
* "Reading helps improve vocabulary." Here, "reading" is the subject, but it's a gerund (a verb form acting as a noun).
* "Running is good exercise." Similar to the above, "running" is a gerund acting as the subject noun.
* "To be or not to be, that is the question." "To be or not to be" is a noun phrase acting as the subject, even though it's comprised of infinitive verbs.
Important Note: Sometimes, it can be tricky to identify the subject when a sentence uses a pronoun. Here's an example:
* "It is raining." While "it" is the subject, it doesn't have the same concrete meaning as the examples above. In this case, "it" acts as a placeholder for the weather condition, making it less obvious that it's acting as a noun.
Let me know if you'd like more examples or have specific questions about subjects as nouns!