Sentence diagram

The Reed–Kellogg system was developed by Alonzo Reed and Brainerd Kellogg for teaching grammar to students through visualization.

These basic diagramming conventions are augmented for other types of sentence structures, e.g. for coordination and subordinate clauses.

Constituency is a one-to-one-or-more relation; every word in the sentence corresponds to one or more nodes in the tree diagram.

Dependency, in contrast, is a one-to-one relation; every word in the sentence corresponds to exactly one node in the tree diagram.

The one-to-one-or-more constituency relation is capable of increasing the amount of sentence structure to the upper limits of what is possible.

Thus the vertical and slanting lines that cross or rest on the baseline correspond to the constituency relation.