One of the first batch of words that students of Japanese usually learn is the 「こ」、「そ」、「あ」、「ど」 series of words for things and locations.
- これ – this
- それ – that
- あれ – that (over there)
- どれ – which
- ここ – here
- そこ – there
- あそこ – over there
- どこ – where
Most will also probably learn the shortened version of 「これの」 etc. such as 「この」. And that’s usually about all that’s ever covered even though there’s a bunch more 「こ」、「そ」、「あ」 vocabulary that are really useful! So let’s look at a few.
Like this/that
You know how you’re not supposed to use the word “like” all the time. Well, we all do anyway because it’s so useful, right? The 「こう、そう、ああ」 series of words are arguably just as useful.
If somebody asks you how to do something, one common answer is “do it like this or that” and that’s exactly what 「こう、そう、ああ」 means. Now you see where 「そうです」 comes from.
A: この漢字はどう書くんですか？
A: How do you write this Kanji?
B: こう書きます。
B: You write it like this.
The real power from these words come when you combine them with 「いう」 to define what something is like. The English equivalent would be “this/that kind of thing”. It’s a great way to talk about abstract or complicated matters.
Examples
- そういう難しい話は、よくわかんないよ。
I don’t understand that kind of difficult talk (topic).
- こういう時には、本当に何もする気がないんだよな。
Really don’t feel like doing anything in times like these.
You can extend this further by attaching 「風」 (pronounced 「ふう」 in this case), to describe a certain way of doing things.
- この漢字はこういう風に書くのよ。
You write this Kanji in this kind of style/manner.
This/that much?
Another incredibly useful series of words are: 「こんな、そんな、あんな」. Combined with the 「に」 particle, these words will allow you to say common things like “Are you that hungry?” or “Did you have to buy this much?”. You can also use them without the 「に」 particle but the meaning is a bit hard to explain and is not used as often (in my opinion).
Examples
- そんなにお腹が空いているの？
Are you that hungry?
- こんなにたくさん買う必要があったの？
Did you have to buy this much?
Comparison
If you’ve learned the grammar for comparisons, you are probably already familiar with the phrase 「どちらの方が」. This literally means “which way” which you can obviously answer with “this or that way”. It can also be used for plain directions as well, of course.
- こちら – this
- そちら – that
- あちら – that (over there)
Etc
There are others like 「こいつ、そいつ、あいつ」 that I’m not going to discuss here. I don’t want to be accused of corrupting the pure and proper Japanese that is taught in most classes. 
