MISHNA: How is the hoof deemed forewarned - that is to say, for what [type of damage that it does] is the hoof forewarned?

Breaking in the course of its walking - that is to say, it is thus that it is forewarned, in that it [typically] breaks things in the course of its walking.

An animal is forewarned, etc. - the gemara will ask that "hoof" [the first clause] is the same as "animal" [the second class]; it already taught about "breaking in the course of its walking".

If it was kicking - this is a difference [from its normal behavior] and [is thus] a subcategory of Horn; therefore [the owner is liable to] half damages and no more.

Or that pebbles were propelled from under its feet, etc. - even though this is not a difference, but rather is its normal behavior, nevertheless [the owner is liable to] half damages and no more, because it is a halakha learned through tradition. This [ruling] is stated [regarding damage that occurred] in the property of the injured party, since [if it had occurred] in the public domain [the owner] would be exempt, as was established at the beginning of the first chapter [Bava Kamma 3b:12]: that pebbles are a subcategory of Hoof in that they exempt [the owner of the animal for damage caused] in the public domain.

And it fell upon a vessel - another [vessel].

First - [damage to the first vessel] is considered Hoof damage, and [the owner] must pay full [damages]. The latter [vessel] was broken by Pebbles; therefore [the owner pays only] half damages.

A delil tied to its leg - anything tied to the chicken's leg is called delil; others have the text as deli.

Hopping - i.e., dancing.

Pays half the damage - since a delil is equivalent to Pebbles, as is explained by the gemara, that [the chicken] moved [the delil] [Bava Kamma 19b:10]. So too hopping, where for example the pebbles sprayed out and broke the vessels.