You can use the keyboard to move the cursor forward or backward one character or one word at a time. You can also delete the character or word to the right or the left of the cursor, and you can move the cursor to the beginning or end of a line.
Getting out of an Expression
Move to the end of the next-higher subexpression by pressing Ctrl and Space at the same time.
Press Ctrl+Space repeatedly.
Selecting the Next Placeholder
Select the next placeholder by pressing the Tab key.
Pressing the Tab key.
Press Tab repeatedly.
Select the previous placeholder by pressing Shift and Tab at the same time.
Press Shift and Tab at the same time.
Press Shift+Tab repeatedly.
Move back and forth between complementary positions by pressing Ctrl+5 or Ctrl+%.
First, alternate between a radicand and an index.
Next, alternate between a superscript and a subscript.
Finally, alternate between an overscript and an underscript.