こんな・そんな・あんな（こう・そう・ああ）
…like this / like that / like that over theremachine translation
Formationこんな・そんな・あんな + noun; こう・そう・ああ + verb / adjective
The trio こんな・そんな・あんな extends the この・その・あの system you mastered at N5, but instead of pointing to a specific thing, they describe its QUALITY or KIND: この町 is "this town", while こんな町 is "a town like this". The near–far division stays the same: こんな is near the speaker, そんな belongs to the listener's side or to something just mentioned, あんな is for something both of you know but distant from you both.
To modify a verb or adjective instead of a noun, use the corresponding adverb set こう・そう・ああ ("in this/that way"): この漢字はこう書きます (this kanji is written like this). You've actually been using そう for a long time in そうですね、そう思います — that's a member of this set.
Adding に to make こんなに・そんなに・あんなに shifts the meaning to DEGREE, "to this/that extent": そんなに高くないです (it's not that expensive). そんな on its own is also a familiar conversational reaction: そんなことはありません (no such thing / not at all).
Examples
こんな町に住みたいです。
I'd like to live in a town like this.
そんな話は聞いたことがありません。
I've never heard a story like that.
この漢字はこう書きます。
This kanji is written like this.