This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
The isAlive method returns true if the thread has been started and not stopped. If the isAlive method returns false, you know that the thread either is a New Thread or is Dead. If the isAlive method returns true, you know that the thread is either Runnable or Not Runnable. You cannot differentiate between a New Thread or a Dead thread. Nor can you differentiate between a Runnable thread and a Not Runnable thread.