I use pen tool to draw around of shapes in my sketch in illustrator , during drawing I do wrong and the path is closed , I want to continue from one point of this path but I don't know how do it by pen
here is a picture of my probelm
Undo the last click (Ctrl+Z for Windows, Command+z for Mac) and with the Pen tool selected, hover over the last node you created and it should change to a '/'. When you click the node you'll be adding on to the path you created.
I also suggest changing your fill color to transparent until you've completed the path so you can see your sketch underneath completely.
If the file is still open, follow OghmaOsiris' answer.
If the file was closed and/or undo is not available, use the *Direct Selection Tool * (White arrow) to click the section of path you do not want, and then tap the Delete key. Only that section should be removed. You can then use the pen tool to click one of the end anchors and continue drawing the path.
The above works, but if you don't want to delete and endpoint to continue drawing your path try this:
For a previously left open path:
Using the Selection Tool shortcut - "v"
Click to select object/path
Double click to open path in isolation mode
Pen tool "p"
Click on endpoint with pen tool - will have "/" icon hopefully.