Sometimes it is useful to cut off input method processing so that the characters you have just entered will not combine with subsequent characters. For example, in input method latin-1-postfix, the sequence e ' combines to form an e with an accent. What if you want to enter them as separate characters?
One way is to type the accent twice; this is a special feature for entering the separate letter and accent. For example, e ' ' gives you the two characters e'. Another way is to type another letter after the e--something that won't combine with that--and immediately delete it. For example, you could type e e <DEL> ' to get separate e and '.
Another method, more general but not quite as easy to type, is to use C-\ C-\ between two characters to stop them from combining. This is the command C-\ (toggle-input-method) used twice.
C-\ C-\ is especially useful inside an incremental search, because it stops waiting for more characters to combine, and starts searching for what you have already entered.
The variables input-method-highlight-flag and input-method-verbose-flag control how input methods explain what is happening. If input-method-highlight-flag is non-nil, the partial sequence is highlighted in the buffer (for most input methods--some disable this feature). If input-method-verbose-flag is non-nil, the list of possible characters to type next is displayed in the echo area (but not when you are in the minibuffer).
Input methods are implemented in the separate Leim package: they are available only if the system administrator used Leim when building Emacs. If Emacs was built without Leim, you will find that no input methods are defined.
