PLEASE NOTE: THIS IS AN OLD VERSION. The current version is linked from The Complete Lojban Language.

4. The universal ``bu''

So far we have seen ``bu'' only as a suffix to vowel cmavo to produce vowel lerfu words. Originally, this was the only use of ``bu''. In developing the lerfu word system, however, it proved to be useful to allow ``bu'' to be attached to any word whatsoever, in order to allow arbitrary extensions of the basic lerfu word set.

Formally, ``bu'' may be attached to any single Lojban word. Compound cmavo do not count as words for this purpose. The special cmavo ``ba'e'', ``za'e'', ``zei'', ``zo'', ``zoi'', ``la'o'', ``lo'u'', ``si'', ``sa'', ``su'', and ``fa'o'' may not have ``bu'' attached, because they are interpreted before ``bu'' detection is done; in particular,

4.1)  zo bu
    the word ``bu''
is needed when discussing ``bu'' in Lojban. It is also illegal to attach ``bu'' to itself, but more than one ``bu'' may be attached to a word; thus ``.abubu'' is legal, if ugly. (Its meaning is not defined, but it is presumably different from ``.abu''.) It does not matter if the word is a cmavo, a cmene, or a brivla. All such words suffixed by ``bu'' are treated grammatically as if they were cmavo belonging to selma'o BY. However, if the word is a cmene it is always necessary to precede and follow it by a pause, because otherwise the cmene may absorb preceding or following words.

The ability to attach ``bu'' to words has been used primarily to make names for various logograms and other unusual characters. For example, the Lojban name for the ``happy face'' is ``.uibu'', based on the attitudinal ``.ui'' that means ``happiness''. Likewise, the ``smiley face'', written ``:-)'' and used on computer networks to indicate humor, is called ``zo'obu'' The existence of these names does not mean that you should insert ``.uibu'' into running Lojban text to indicate that you are happy, or ``zo'obu'' when something is funny; instead, use the appropriate attitudinal directly.

Likewise, ``joibu'' represents the ampersand character, ``&'', based on the cmavo ``joi'' meaning ``mixed and''. Many more such lerfu words will probably be invented in future.

The ``.'' and ``,'' characters used in Lojbanic writing to represent pause and syllable break respectively have been assigned the lerfu words ``denpa bu'' (literally, ``pause bu'') and ``slaka bu'' (literally, ``syllable bu''). The written space is mandatory here, because ``denpa'' and ``slaka'' are normal gismu with normal stress: ``denpabu'' would be a fu'ivla (word borrowed from another language into Lojban) stressed ``denPAbu''. No pause is required between ``denpa'' (or ``slaka'') and ``bu'', though.