Fragments, Run-ons, and Sentences

A sentence must have a subject and predicate, and it must express a complete thought.
Fragments are incomplete sentences. They are usually missing a subject, predicate, object, or independent clause. They do not complete a thought.
Run-ons are made of two or more independent clauses joined without using the correct connecting words and/or punctuation.

Forms:
Fragment
This is missing a part of the sentence

▓ While attending classes on 18th and 19th century European art.
(missing a clause with the subject)

Run-on
This is missing a word and/or punctuation mark to combine two or more sentences.		 Gina and Zach worked on several art projects ▓ there were also classes on 18th and 19th century European art.
 (missing a connecting word and/or punctuation mark)
Complete Sentence Gina and Zach worked on several art projects while attending classes on 18th and 19th century European art.
or
Gina and Zach worked on several art projects, and they attended classes on 18th and 19th century European art.
or
Gina and Zach worked on several art projects. They also attended classes on 18th and 19th century European art.