さえ～ばIf only…then, As long as..., Provided..., Only thing ... needs for ... is ...

As a set expression, さえ～ば is a combination of the adverbial particle さえ, and the conjunction particle ば. It is used to highlight assumption, and presents (A) as a extreme limitation that is required to achieve (B), hypothetically. This structure may be translated as 'if only (A), then (B)', 'the only thing needed for (B) is (A)', or 'as long as (A), (B)'.

さえ may be grouped with any word, but will require the conjunctive form, or て form before it when grouped with verbs. It also regularly appears after other particles, forming a dual-particle meaning.

This use of さえ is an example of limit, with (A) being a hypothetical limit presented by the ば particle. It is also possible to see さえ with other hypothetical indicators (such as たら), but is quite rare in modern Japanese, as さえ～ば is considered a set pattern.

This limitation is also sometimes referred to as a 'stipulation', or 'condition'.