Subject: Who or what the sentence is about
Predicate: what the subject does or is
Sentences that are missing the subject or predicate are called fragments. A fragment is an incomplete thought.
Run-on sentences are sentences that include more than one complete thought without the use of a punctuation mark to separate those complete thoughts.
Proper Nouns
Beginning of a sentence
The word I
Days, months, and holidays
Titles of people (Mr., Mrs., Dr.)
Titles of books, movies, and TV shows
Nationalities, religions, and languages