Filter words

Filter words are verbs of perception and cognition — saw, felt, heard, noticed, watched, realized, wondered, knew — that place the viewpoint character between the reader and the experience. "She saw the door swing open" filters the moment through her act of seeing; "The door swung open" delivers it directly.

The cost is narrative distance. In a close point of view, the reader is already inside the character's perception, so announcing "she heard" or "he felt" is redundant scaffolding: it reminds the reader they are watching someone perceive rather than perceiving alongside them. Cutting the filter usually makes the sentence shorter, more immediate, and more vivid at the same time.

They are not always wrong. A filter word earns its place when the act of perceiving is itself the point — "She realized the room had gone quiet" marks the moment of realization, not just the quiet. Filters also help in distant or omniscient narration, and an occasional one can pace a paragraph. The craft habit is to search a draft for them and make each one justify itself.