VERBAL AGREEMENT

The following four words share an unusual property. Can you determine what it is?

SEE
FALL
BEAR
GRIND

HINT:
It has to do with verb tenses.

Answer:

Each word is a present tense verb with an irregular past tense. Each of these past tenses is a regular verb in its own right - with a regular past tense:

SEE - SAW - SAWED
FALL - FELL - FELLED
BEAR - BORE - BORED
GRIND - GROUND - GROUNDED

NOTE 1: LIE could be added to the list, but it also has an irregular past tense:

LIE - LAY - LAID

NOTE 2: BORE is a homograph:
The machine can bore through solid rock.
You bore me with your constant whining.