Let me give you an informal behavioural definition of T9: It is that type of text input on your phone that underlines your text as you type and often seems to show you a character different from the intended one. I can tell you it is a great and fast way of composing text and chat messages. Many people don't know how to use it. I, myself, didn't know how to use it. I would say to myself, "What sort of rubbish is this?", "How on earth do they expect me to type that word?" I said these because as I pressed the keys, they seemed to turn up unintended characters. For example, if I wanted to type consult, before I could finish, such meaningless word as accommon might turn up, leaving me frustrated. I had to turn off the feature and adopt the traditional, multi-tap ABC. Then out of curiosity, interest and trial and error, I was able to learn the T9 feature. Very simple. Today it is about the only text input method I use on my mobile phones.
How to Turn the T9 Feature On and Off on Mobile Phones
T9 seems to be on by default on newer mobile phones. However, if it is not activated, you can turn it on through the Message menu. Generally, T9 can be turned on by opening the text input environment on your phone, clicking Options, scrolling to Dictionary or T9 and selecting a desired language (English). It can also be turned on by pressing the hash key (#) severally until its indicator is shown (the text input environment has to be on when pressing the # key). Its indicator often looks like a double line under a pencil and the letters Abc or ABC to the right of the pencil.
Let me use Nokia 1280 as an example: To activate the T9 feature, go to Menu > Messages > Select > Create Message > Select > Options > Scroll to Dictionary > Select > English > OK. The shows T9 Dictionary On and the T9 indicator appears. It can be turned off by using the format: Menu > Messages > Select > Create Message > Select > Options > Scroll to Dictionary > Select > Dictionary Off > OK.
Depending on the phone you are using, the diction and order may be different, but the principle is the same.
How to Use the T9 Feature
T9 is predictive in nature as it attempts to anticipate what you want to type based on your key presses. It allows words to be entered by a single key press for each letter. T9 makes use of an updatable dictionary. It looks up in the dictionary all words corresponding to the sequence of your key presses and orders them by frequency of use.
Let me offer some examples: if you use the traditional Multi-tap ABC and you want to type the word, Mobile, you normally press Key 6 (mno) once for letter M, the same Key 6 three times for letter O, Key 2 (abc) two times for letter B, Key 4 (ghi) three times for letter I, Key 5 (jkl) three times for letter L and Key 3 (def) two times for letter E. But for T9, if you want to type the word, Mobile, press Key 6 (mno) two times, Key 2 (abc) one time, Key 4 (ghi) one time, Key 5 (jkl) one time and Key 3 (def) one time. If you want to type the word, Any, press Keys 2 (abc), 6 (mno) and 9 (wxyz) once each. The explanation is found in the fact that, in a basic phone keypad, the letters A, N and Y are printed or engraved on Keys 2, 6 and 9. During the input, just ignore whatever letters or characters the display shows. After the input, the T9 feature, using its internal dictionary, will predict the intended word based on your key presses. If it happens that the shown word is not what you intend, you can browse through alternative words by repeatedly pressing the * Key until the desired word is shown. In the case of the word, Any, pressing the * Key could turn up such words as Boy, Box, Bow, Cow, Cox, Coy, etc. The group of words may be called textonyms. This is because you pressed Keys 2, 6 and 9 and all the letters of the listed words are associated with the keys. Letters A, B and C are found on Key 2, letters M, N and O on Key 6 and letters W, X, Y and Z on Key 9. They are produced by the same combination of key presses.
In some cases, the intended word is not available in the T9 dictionary. Fortunately enough, the dictionary is updatable. You can add words to it so that such words could now be shown based on your key presses. Still using Nokia 1280 as an example, if you attempt to enter a number that is not currently in the dictionary, it will attach a question mark to the word and the option Spell appears on the phone screen. Select Spell and enter the word using the traditional Multi-tap. Press OK after that. The word is now is added to the dictionary. Next time, the newly added word could turn up as you press the * button to browse through possible words based on your key presses. You can also enter word when you are in the environment for typing messages by going through Options > Scroll to Insert Options and select it > Scroll to Insert Word and select it > Enter the word and press OK.
In the case of a compound word such as fast-track, enter the first part of the word (in this case fast):
- Key 3 (def) once
- Key 2 (abc) once
- Key 7 (pqrs) once
- Key 8 (tuv) once (if fast is not showing up, repeatedly press the * Key until it turns up)
- press the forward-direction key (>) once
- long-press the * Key to reveal a list of symbols and punctuations
- scroll to - and select Use
- Key 8 (tuv) once
- Key 7 (pqrs) once
- Key 2 (abc) twice, and
- Key 5 (jkl) once