In a similar way to how the particle こそ highlights a particular word as being the 'precise' or 'exact' reason for something, its combination with the て-form of a verb will indicate that (B) is absolutely reliant on (A). This reliance can be translated in several different ways, and will usually become clear in the (B) part of sentences. Standard interpretations include 'only if (A), (B)', 'unless (A), (B)', or 'until (A), (B)'.

• 海外（かいがい）に留学（りゅうがく）してこそ、日本食（にほんしょく）の美味（おい）しさが分（わ）かる。
  Only by studying abroad can one appreciate the deliciousness of Japanese food.
• 親（おや）になってこそ、子育（こそだ）ての大変（たいへん）さがわかる。
  It is only when you become a parent that you understand how hard it is to raise a child.
• チーム全員（ぜんいん）の責任（せきにん）を背負（せお）ってこそ、キャプテンになれる。
  You become a captain only if you take on the responsibility of the whole team.
• 他（ほか）のチームに勝（か）ってこそ、世界一（せかい）になれる。
  Only by beating other teams can we become the best in the world.

The reliance that (B) has on (A) can be translated in several different ways, but the most common interpretations are that (A) will determine either the outcome, assessment, or evaluation of (B), based on the speaker's opinion, values, or understanding of the situation.