Koboshi

For multilinguals and polyglots

Built for multilingual minds.

Most vocabulary tools assume one native language and one target. Koboshi is built for people who carry several.

The line that matters

Strengthen every language you know, while you learn the next one.

Look a word up once, see it across the languages you know, and every one of them gets sharper.

Every language you speak lives in one language knowledge base, so a word saved in Spanish is already linked to what you hold in Japanese and English.

Your languages help each other. Koboshi connects them.

One search, every nuance

Search once. See the word across your languages, each with its own nuance.

Save the one that clicks

An idea clicks in one language, sometimes another. Koboshi works that way too.

Each on its own schedule

Save the versions you want. Each language reviews on its own clock.

propitious carries two senses
one idea propitious
propicio
pro-PEE-syo C1
🇪🇸 Spanish

Favorable, well suited to the moment.

el momento propicio para actuar the right moment to act

Synonymsfavorable · oportuno

絶好の
zekkō no B2
🇯🇵 Japanese

Ideal. The perfect conditions or timing.

絶好の機会 a perfect opportunity

Synonyms最適な · うってつけの

سازگار
sāzgār B2
🇵🇰 Urdu

Favorable, agreeable, conducive.

حالات سازگار ہیں conditions are favorable

Synonymsموافق · مناسب

Your strong languages get stronger too

Your vocabulary stops being lists. It becomes a map.

Every word you save links to the idea behind it, and to that idea in your other languages. Polyglots have always learned this way; Koboshi keeps the links.

Built for non-linear language lives

Set each language's role, and change it any time.

Pick each language's role

Choose your base, learning, and input language. Change the roles in settings in seconds.

One system, no mixed list

Keep all your languages in one system, without one messy mixed list to scroll through.

Spot the false friends

Compare meanings, spot false friends, and find cognates across your languages, so look-alikes stop tricking you.

Questions

What polyglots ask first.

Can I learn two languages at the same time?

Yes, with one caution: two similar languages from zero at once, like Spanish and Italian, tend to blur together. One new language plus strengthening the ones you already have works best, and that is the mix Koboshi is built for.

Do I have to use English as my base?

No. You choose your base, learning, and input languages, and you can change them anytime in settings.

I speak several languages but none feel native. Will this help?

Yes. The cross-language view uses your strongest languages to deepen the others, and the reviews keep all of them warm.

How is this different from running several single-language apps?

Those keep each language in its own box. Koboshi connects them.

Every language you carry, in one knowledge base.

Connect the languages you already carry.