てこそ | Grammar

Structure

[verb て-form] + こそ

Description

てこそ means "only by ~" or "only once you have ~". It goes after the て-form of a verb, and the second half is a result, or an understanding, that the action alone makes possible.

、。

Only by making an effort can you succeed.

、。

It is by failing that people grow.

、。

Only when you get sick do you appreciate good health.

picks out "this and nothing else", so the action before it becomes the one condition that counts. The second half is positive – something achieved, something understood – and it is a general truth, so it stays in the non-past. A single past realisation takes instead.

、。

It was only when I tried it that I understood how hard it was.

× やってみてこそ、難しさが分かった → やってみて初めて、難しさが分かった

てこそ or からこそ

picks out a reason: "precisely because". てこそ picks out a condition: "only if you do".

、。

It's precisely because I worked hard that I succeeded.

、。

Only by working hard can you succeed.

Register

てこそ sounds weighty: a maxim, a speech, an essay. In conversation, ないと with a negative says the same thing more plainly.

、。

You won't know until you try it yourself.

Examples

、。

Only by making an effort do dreams come true.

、。

Only by experiencing it yourself can you understand the truth.

、。

It is precisely by failing that you learn what to do next.

、。

Only through hardship does one come to understand the meaning of happiness.

、。

Only by living abroad do you notice the good things about your own country.

、。

Only by understanding each other can you build a good relationship.

、。

Only by actually trying it do you understand how difficult it is.

、。

Only by living alone do you appreciate your parents.

、。

Only when every team member cooperates can this work be completed.

、。

It is only by practicing many times that you can become skilled.

、。

People become stronger only by overcoming difficulties.

、。

Only by raising children does one truly understand a parent's feelings.

References

-てこそBunpro