こそあど (これ・この・ここ・こちら…): this / that / that over there / which: the whole family
Japanese points at things with four sets of words that start with こ (near me), そ (near you), あ (over there, far from both of us) and ど (which?).
<table class="kso"><tr><th></th><th>こ near me</th><th>そ near you</th><th>あ over there</th><th>ど which?</th></tr><tr><td>thing (alone)</td><td>これ</td><td>それ</td><td>あれ</td><td>どれ</td></tr><tr><td>+ noun</td><td>この</td><td>その</td><td>あの</td><td>どの</td></tr><tr><td>place</td><td>ここ</td><td>そこ</td><td>あそこ</td><td>どこ</td></tr><tr><td>direction (polite)</td><td>こちら</td><td>そちら</td><td>あちら</td><td>どちら</td></tr></table>この・その・あの・どの always come before a noun: あの人 "that person", この本 "this book". これ・それ・あれ・どれ stand alone. In stories, あの and その also point back to something both people already know.
Examples
あの人は、どこから来たのですか。
Where did that person come from?
この本は、そこにあった本です。
This book is the one that was there (near you).