限り|かぎり

1. 1As long as a condition or state continues, the situation in the main clause holds.Ex. 1
2. 2With a negative form (ない限り), 'unless': the main clause holds unless the condition happens.Ex. 2
3. 3Within the limits of, or as far as, as in 私の知る限り (as far as I know) and できる限り (as much as possible).

限り sets a condition whose continuation guarantees the result, and it often carries a sense of commitment or firm judgment. It appears in both speech and writing, and fixed expressions such as できる限り and 私の知る限り are very common. Compared with plain ば, it stresses that the result holds only while the condition lasts.

• 〜さえ〜ばN3「〜さえ〜ば」 overlaps with this pattern only in its 'as long as / provided that' meaning; it stresses that the preceding element is the sole minimum condition, can be used with one-time actions, and can also take 「のに」 to express regret. 「限り」, by contrast, focuses on the span over which a state continues and sounds more formal.
• 〜てさえいればN2「〜てさえいれば」 corresponds only to the 'as long as... then...' reading of 「限り」, emphasizing the single necessary condition. 「限り」 centers on the range over which the condition holds, often expressing resolve or stating rules, and carries additional meanings such as 'unless' and 'as far as... knows'.
• に限ってN2「に限って」 attaches to nouns or to 「時／日」 and typically means something bad happens precisely at that moment, or expresses exclusive trust in someone. 「限り」 instead means 'as long as a state lasts' or marks a limit of scope. The two come close when limiting things to a specific occasion, as in 「今回に限って」 vs. 「今回限り」, though the nuance differs slightly.
• に限るN2「に限る」 functions as a sentence-final predicate meaning 'it's best to...' or 'is limited to...'; 「限り」 means 'as long as', 'unless', or 'as far as... knows', usually followed by a main clause, and can also modify nouns as in 「できる限りの」. They cannot replace each other.
• うちにN3When 「限り」 works as a conditional, the second clause holds throughout the period during which the first state continues; 「うちに」 means doing something before the state changes ('while') or describes change occurring unnoticed within a process, so they are not interchangeable. Note that 「ないうちに」 means 'before (something happens)', while 「ない限り」 means 'unless'.
• ばN4「ば」 has broader uses—it can mark hypotheticals, general regularities, and one-time actions—whereas 「限り」 emphasizes that the second clause holds for as long as the state persists, giving a more solemn tone. When both express conditions on continuing states, they are largely interchangeable.

〜さえ〜ば and 〜てさえいれば say that one condition alone is enough, whereas 限り stresses that the result lasts as long as the condition does. ば is a general conditional without this sense of duration. に限って means 'only in this case (unexpectedly)' and に限る means 'X is best'. うちに means doing something while a state lasts, before it changes, rather than setting a condition.