Use 'border on' to express strong emotions or actions that are almost excessive.

Emotional Intensity

'Border on' suggests that something is almost negative or undesirable.

Negative Connotation

At times, 'border on' can imply a positive quality taken to an admirable limit.

'Border on' helps emphasize when a quality is almost inadequate or irresponsible.

Use 'border on' when evaluating something that’s almost, but not quite, a certain way.

'Border on' often appears in less formal conversations and literature.