What is the proper hand signal for a left turn?

The proper hand signal for a left turn is to extend your left arm straight out of the window. This signal clearly indicates to other drivers and pedestrians that you plan to make a left turn. Using this arm signal serves as an important communication tool on the road, particularly when blinkers or indicators may be faulty or not visible.

While extending your left arm at a 90-degree angle is typically used for a right turn, extending your right arm straight out is not a standard signaling method for a turn at all. Additionally, extending both arms out the window does not convey any specific turning intention and could confuse other road users. Thus, extending your left arm straight out effectively fulfills the requirement to signal a left turn in a clear and understood manner.