where should you begin a left turn from a one-way street onto a one-way street?

You should begin a left turn from a one-way street onto a one-way street by moving into the left lane closest to the left curb. After signaling and checking for traffic, slow down and start your turn from as close as possible to the left edge of the roadway. Complete the turn into the left-most lane of the street you are entering unless that lane is blocked within about 30 meters of the intersection. This is the correct and safest way to make such a turn, and unless otherwise indicated by signs, you may also make this left turn on a red light after stopping and yielding to pedestrians and other traffic.