Different cultures express emotions and attitudes with a variety of intonations and gestures that are not usually included in written language. Some of these are available in some languages as interjections (i.e. Aha!, Oh no!, Ouch!, Aahh!, etc.), but they vary greatly from culture to culture.
Lojban has a group of cmavo known as “attitudinal indicators” which specifically covers this type of commentary on spoken statements. They are both written and spoken, but require no specific intonation or gestures. Grammatically they are very simple: one or more attitudinals at the beginning of a bridi apply to the entire bridi; anywhere else in the bridi they apply to the word immediately to the left. For example:
16.1) .ie mi [cu] klama Agreement! I go. Yep! I’ll go. 16.2) .ei mi [cu] klama Obligation! I go. I should go. 16.3) mi [cu] klama le melbi .ui [ku] I go to the beautiful-thing (and I am happy because it is the beautiful thing I’m going to).
Not all indicators indicate attitudes. Discursives, another group of cmavo with the same grammatical rules as attitudinal indicators, allow free expression of certain kinds of commentary about the main utterances. Using discursives allows a clear separation of these so-called “metalinguistic” features from the underlying statements and logical structure. By comparison, the English words “but” and “also”, which discursively indicate contrast or an added weight of example, are logically equivalent to “and”, which does not have a discursive content. The average English-speaker does not think about, and may not even realize, the paradoxical idea that “but” basically means “and”.
16.4) mi [cu] klama .i do [cu] stali I go. You stay. 16.5) mi [cu] klama .i ji'a do [cu] stali I go. In addition, you stay. (added weight) 16.6) mi [cu] klama .i ku'i do [cu] stali I go. However, you stay. (contrast)Another group of indicators are called “evidentials”. Evidentials show the speaker’s relationship to the statement, specifically how the speaker came to make the statement. These include “za'a” (I directly observe the relationship), “pe'i” (I believe that the relationship holds), “ru'a” (I postulate the relationship), and others. Many American Indian languages use this kind of words.
16.7) pe'i do [cu] melbi I opine! You are beautiful. 16.8) za'a do [cu] melbi I directly observe! You are beautiful.