19.4. Topic-comment sentences: ZOhU

The following cmavo is discussed in this section:



topic/comment separator

The normal Lojban sentence is just a bridi, parallel to the normal English sentence which has a subject and a predicate:

Example 19.2. 

mi klama le zarci

I went-to the market

In Chinese, the normal sentence form is different: a topic is stated, and a comment about it is made. (Japanese also has the concept of a topic, but indicates it by attaching a suffix; other languages also distinguish topics in various ways.) The topic says what the sentence is about:

Example 19.3. 

  • zhe4 xiao1xi2 : wo3 zhi1dao le

  • this news : I know [perfective]

  • As for this news, I knew it.

  • I've heard this news already.

The colon in the first two versions of Example 19.3 separate the topic (this news) from the comment (I know already).

Lojban uses the cmavo zo'u (of selma'o ZOhU) to separate topic (a sumti) from comment (a bridi):

Example 19.4. 

le nuzba zo'u mi ba'o djuno
The news : I [perfective] know.

Example 19.4 is the literal Lojban translation of Example 19.3. Of course, the topic-comment structure can be changed to a straightforward bridi structure:

Example 19.5. 

mi ba'o djuno le nuzba
I [perfective] know the news.

Example 19.5 means the same as Example 19.4, and it is simpler. However, often the position of the topic in the place structure of the selbri within the comment is vague:

Example 19.6. 

le finpe zo'u citka
the fish : eat

Is the fish eating or being eaten? The sentence doesn't say. The Chinese equivalent of Example 19.6 is:

Example 19.7. 

  • yu2: chi1

  • fish: eat

which is vague in exactly the same way.

Grammatically, it is possible to have more than one sumti before zo'u. This is not normally useful in topic-comment sentences, but is necessary in the other use of zo'u: to separate a quantifying section from a bridi containing quantified variables. This usage belongs to a discussion of quantifier logic in Lojban (see Section 16.2), but an example would be:

Example 19.8. 

ro da poi prenu ku'o
For-all X which are-persons,
su'o de zo'u de patfu da
there-exists-a Y such-that Y is-the-father-of X.

Every person has a father.

The string of sumti before zo'u (called the prenex: see Section 16.2) may contain both a topic and bound variables:

Example 19.9. 

loi patfu ro da poi prenu ku'o
For-the-mass-of fathers for-all X which are-persons,
su'o de zo'u de patfu da
there-exists-a Y such-that Y is-the-father-of X.

As for fathers, every person has one.

To specify a topic which affects more than one sentence, wrap the sentences in tu'etu'u brackets and place the topic and the zo'u directly in front. This is the exception to the rule that a topic attaches directly to a sentence:

Example 19.10. 

loi jdini zo'u tu'e   do ponse .inaja do djica [tu'u]
The-mass-of money : ( [if] you possess, then you want )

Money: if you have it, you want it.

Note: In Lojban, you do not want money; you want to have money or something of the sort, as the x2 place of djica demands an event. As a result, the straightforward rendering of Example 19.9 without a topic is not:

Example 19.11. 

do ponse loi jdini .inaja do djica ri
You possess money only-if you desire its-mere-existence.

where ri means loi jdini and is interpreted as the mere existence of money, but rather:

Example 19.12. 

do ponse loi jdini .inaja do djica tu'a ri
You possess money only-if you desire something-about it.

namely, the possession of money. But topic-comment sentences like Example 19.10 are inherently vague, and this difference between ponse (which expects a physical object in x2) and djica is ignored. See Example 19.45 for another topic/comment sentence.

The subject of an English sentence is often the topic as well, but in Lojban the sumti in the x1 place is not necessarily the topic, especially if it is the normal (unconverted) x1 for the selbri. Thus Lojban sentences don't necessarily have a subject in the English sense.