this (thing/person/idea near the speaker); a pre-nominal demonstrative used before a noun
この本はとても面白い。
This book is very interesting.
この人は私の同僚です。
This person is my colleague.
この問題は少し難しいですね。
This problem is a bit difficult, isn't it?
このアイデアなら成功すると思う。
I think this idea will succeed.
this (as in 'this past' or 'these' referring to a recent period or the immediately preceding time)
この数年で生活が大きく変わった。
Life has changed greatly in these past few years.
この夏は例年より暑かった。
This past summer was hotter than usual.
an emphatic/insulting use as in 'you ...' (e.g., このやろう), used to accuse or insult someone
このやろう、ふざけるな！
You bastard, don't mess around!
この嘘つきが！全部話せ！
You liar! Tell me everything!