How many times can I type an incorrect facebook password?

[Simply RED]

Yes, just one mistake in the password entry and his email account will receive a message containing the following:

=========
Subject: Getting back onto Facebook
Hi <the_username_here>,
Sorry you've been having trouble logging into your Facebook account.
=========

There will also be a link in the message for instant log in. Unless he's the suspicious type, that will probably make him think that somebody tried to log in to his account with a wrong password. Try it on your FB account, put an incorrect password just once and check your email. You'll see that message in your inbox.

After every 3 incorrect tries, you will be required to fill up the captcha box before you can continue. Once you have correctly filled in the captcha box, you will again have three tries to guess his password but he won't be notified anymore. The notification is only on the first failed attempt.

However, I think after 24 hours, the notification counter for the 1st failed try is reset so if you make a failed attempt again the next day, he will be notified again.