How do you draw a straight line directly after making a Bezier curve with the pen tool (without breaking from the path)?

I see countless YouTube videos where people start out tracing a bitmap using the pen tool with a curve, and then directly make a straight line afterward. Everytime I attempt this, I get a really awkward curve as the next line, and I cannot straighten it out, without altering the first curve. Very frustrating.

Please help a n00b.

There's a keyboard shortcut for it - Shift + L.

From the manual: http://tavmjong.free.fr/INKSCAPE/MANUAL ... ths-Bezier

To change an unfinished segment (the red line) from a curve to a line, use Shift+L. To change an unfinished segment from a line to a curve, use Shift+U.

You are a life saver! Thank you so much!