What is word completion on my Nokia N900?

If word completion is activated, the device suggests suitable endings for the words that you start writing. Word completion is based on a built-in dictionary. When you enter characters, the device searches its dictionary for words starting with these characters.You can select to use dual dictionaries to allow the device to search from the dictionary of the second language if it cannot find a suitable word in the first language dictionary. The dictionary can learn new words automatically from the text you have entered. Text entered in password fields is not saved in the dictionary.Activate word completion and use dual dictionariesTap the Application menu icon and select Settings > Text input.Accept a suggested wordSelect the suggested word. When using the physical keyboard, press the right arrow key.Reject a suggested wordContinue writing the word. With each character, the device updates its suggestion to suit the characters you have entered.