The Lojban dictionary gives the following definition for the word "tu'a".
tu'a — extracts a concrete sumti from an unspecified abstraction; equivalent to le nu/su'u [sumti] co'e.
The definition is difficult to understand, and most Lojban dictionaries do not have example sentences. The word was necessary to express:
"I practice more than one language."
Which translates to:
mi | crezenzu'e | ta'u | za'u | pa | bangu |
I | practice | | more than | one | language |
A very nice person gave me another example to help me understand the word.
"I try the door."
In a natural language, this can be interpreted as trying to open the door. Someone in real life stands in front of a door with a hand on the handle, what that someone is attempting to do can be inferred by the function of a door. However, Lojban is more literal.
"mi troci lo nu kargau le vorme"
(I try to open the door.)
"tu'a" leaves the specific activity to be inferred.
"mi troci tu'a le vorme."
(I try [something related to] the door.)
#lojban