noun
hypothetical form; conditional form
In modern Japanese grammar, the form of verbs and adjectives that ends in 〜ば, used to express conditions. Contrast with 已然形, the classical realis form.
See also: 已然形 (いぜんけい)
「行けば」の「行け」は仮定形です。
The 'ike' in 'ikeba' is the hypothetical form.
仮定形に「ば」を付
Attaching 'ba' to the hypothetical form expresses a condition.