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# Word formation

The monad `;:` can be useful in figuring out what the words are in a sentence. The word formation primitive takes a string as its right argument, splits it into words, and returns a result with each word in a box. For now, don't worry about what the boxes are, just note how visually helpful they are. You'll learn about boxes in later sections.

       ;: '2 + 3'
    +-----+
    ¦2¦+¦3¦
    +-----+

If you don't see the boxes when you try this on your system, then you are using a font that does not have the line drawing characters. Use the Edit|Configure menu command to select a font that does show the boxes. Alternatives are ISIJ, Terminal, MS LineDraw, Courier New, and Lucida Console. Some require OEM and some Default to get the boxes. When you get one you like, be sure to check Save Config so that it will be used the next time you start J.

       ;: '2.5 + 3e4'
    +---------+
    ¦2.5¦+¦3e4¦
    +---------+

       ;: 'a =. 1 2 3'
    +----------+
    ¦a¦=.¦1 2 3¦
    +----------+

       ;: 'test + 123 NB. this is a comment'
    +--------------------------------+
    ¦test¦+¦123¦NB. this is a comment¦
    +--------------------------------+

       ;: 'def =. ''testing 1 2 3'''
    +----------------------+
    ¦def¦=.¦'testing 1 2 3'¦
    +----------------------+

Note that the following are all J words and each goes in its own box:

    2.5
    3e4
    =.
    1 2 3
    test
    NB. this is a comment
    'testing 1 2 3'

It might surprise you that constants such as `1 2 3` and `'testing 1 2 3'` are J words. This is an important point and understanding it is necessary in reading and writing J sentences.

If you are ever puzzled by a J sentence (it could happen), one of the things you can do is apply `;:` to it to be sure you know the words. You can then worry about the meanings of those words.

Look up `;:` in the J Dictionary. The informal name for `;:` is word formation. Turn to the page for `;` and turn pages until you come to the page that has `;:` in its heading.

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