What is the significance of failing to specify an interval size of the type discussed in Section 5? The Lojban rule is that if no interval size is given, the size of the space or time interval is left vague by the speaker. For example:
6.1) mi pu klama le zarci
I [past] go-to the market.
really means:
At a moment in the past, and possibly other moments as
well, the event “I went to the market” was in progress.
The vague or unspecified interval contains an instant in the speaker’s past. However, there is no indication whether or not the whole interval is in the speaker’s past! It is entirely possible that the interval during which the going-to-the-market is happening stretches into the speaker’s present or even future.
Example 6.1 points up a fundamental difference between Lojban tenses and English tenses. An English past-tense sentence like “I went to the market” generally signifies that the going-to-the-market is entirely in the past; that is, that the event is complete at the time of speaking. Lojban “pu” has no such implication.
This property of a past tense is sometimes called “aorist”, in reference to a similar concept in the tense system of Classical Greek. All of the Lojban tenses have the same property, however:
6.3) le tricu ba crino
The tree [future] is-green.
The tree will be green.
does not imply (as the colloquial English translation does) that the tree is not green now. The vague interval throughout which the tree is, in fact, green may have already started.
This general principle does not mean that Lojban has no way of indicating that a tree will be green but is not yet green. Indeed, there are several ways of expressing that concept: see Section 10 (event contours) and Section 20 (logical connection between tenses).