Example sentences
xué学xiào校zài在zuǒ左biān边。
The school is on the left.
wǒ我de的jiā家zài在nǐ你de的zuǒ左biān边。
My home is on your left.
About this word
左 is a left hand holding a carpenter's square, and 边 is a side, so 左边 is the left side, built exactly like 右边 with a different first character. 左 began as to assist, one hand lending another, and the left-hand sense grew out of the physical picture. A useful bonus: 左右, left and right glued together, means around or approximately, as in 十点左右, around ten.
The story behind the character
左
左 is a left hand holding a tool. The top strokes are 𠂇, a hand, and 工 below is a carpenter's square. Xu Shen wrote 左, 手相左助也: a hand lending a hand. The character meant to assist long before it meant left, which is why 佐 was coined to carry the old sense. 左边 is just a direction now, but the hand is still in there, holding the tool.
边
边 is 辶 (walking) with 力 on the right in its simplified form. The traditional 邊 carried a larger sound element on the right. Xu Shen defined it as 行垂崖也: walking along the edge of a cliff. So the side of a thing is, at root, the edge you do not want to step too close to.