A Concise Guide to English Grammar

The given-new principle described in Section 19.1 explains how individual sentences connect to each other. But connecting sentences is only part of what makes a paragraph feel unified. You have probably encountered writing that moves logically from sentence to sentence yet still feels hard to follow—the ideas are there, but something is missing. Conversely, you have probably encountered writing where the ideas are complex but the prose feels smooth and navigable. The difference often comes down to two related properties: cohesion and coherence.

These terms are sometimes used interchangeably, but they describe different things. Understanding the distinction helps you diagnose different kinds of problems in your own prose.

Cohesion refers to the linguistic ties between sentences:

Coherence is the logical connection of ideas. Text can be cohesive without being coherent if the ideas don’t logically connect.

Both are needed for readable prose.