Brush/pencil not working in Photoshop [2012] [CS5]

[Dan_Bowles]

My brush/pencil tool isn't working in Photoshop CS5...when I try and use it it just makes a dot and doesn't allow me to draw a continuous line...

[BillRhodesPhoto]

should also mention that the mouse works fine doing all the things

[MegKatCar]

Brush presets tip shape, unclick dual brush.

[Kateyyy]

I just experienced the exact same problem and after trying svereal of the solutions offered below without success, quitting and re-opening Photoshop fixed it. Super annoying. 

[Houdini_Bob]

my pen quit working for changing tools: brush, lasso, marquee. I tired alla the above with no help. but I figured it out and I forgot to change the pen dos when clickijg. top one was set to eraser, changed it to left click and it is working as it should be. 

[Patrick21807157edmv]

Set "Mode" to "Normal"