Expands the discussion of coordinate structures started in the previous chapter to another kind to syntactic ambiguity involving a prepositional phrase in the title of the Princeton University introductory linguistics course: Introduction to Language and Linguistics. On one interpretation, the left conjunct is only Language; while on the other, it is Introduction to Language. Each interpretation corresponds to a unique hierarchical structure. To determine why one interpretation is more appropriate than the other, it is necessary to consider the meaning of the words language and linguistics, including how they relate. This leads to a basic discussion of what a language is and what language is from the perspective of modern linguistics. This chapter wraps up the analysis of coordinate structures with a discussion of the use and misuse of coordinate structures in writing. It demonstrates how coordinate structures can be a source of ambiguity, redundancy, and vagueness—all hallmarks of poor writing.