In the canonical trilinear representation, one L1 text line T is matched by two L2 lines, the morphological gloss and the free translation. The morphological gloss of T is interlinear in the sense that it is printed below T and above its free translation into L2. This entails a division of labor between the two L2 representations:
- The morphological gloss represents units of the system of L1.
- The free translation represents the sense of T in its discourse and does this according to the rules of L2.
Consequently, the morphological gloss and the free translation do not double information, but elucidate each other. The free translation is the idiomatic semantic equivalent of the L1 line, the morphological gloss is a representation of its morphological structure. There is therefore no need for the translation to be particularly literal, just as there is no need for the morphological gloss to repeat the morphs that appear in the translation. For instance, a polysemous L1 item will be rendered by its contextual sense in the free translation, but by its generic meaning in the morphological gloss (Rule 7). Unnecessary parallelism between the two L2 lines is redundant; the trilinear canonical representation offers an occasion to provide additional information.
Adapting the gloss to L2 usage as it appears in the translation can also mislead the reader about the L1 construction. In , the generic meaning of the root bit- is ‘come’. If the intransitive construction is expanded by a dispositive (DSP) postpositional phrase, which usually represents a passive agent, a causative interpretation of the verb is implied, as brought out by the translation. If the gloss were ‘bring’ instead of ‘come’, the reader would be mislead about the construction.
| . | tsirú | bit-ë́ | s' | wa̱ |
| Cabecar | cocoa | come-PFV | 1.SG | DSP |
| I brought cocoa | ||||
A supplement to the above may be made for examples in which the reader ignorant of L1 may need help to match the free translation with the gloss. This may happen in either of the following cases:
- The contextual sense of T does not bear any recognizable relationship to the morphological gloss.
- The syntax of the L2 translation differs completely from the syntax of T.
may illustrate case #b.
| . | balam-il | =u | ka'h | Pedro |
| tiger-ADVR | A.3 | do | Peter | |
| Peter makes the tiger / Peter is like a tiger (lit.: ‘tiger-like is what Peter does’; Motul s.v. cah3) | ||||
As shown, the idiomatic translation may be supplemented by a more literal translation in such a case.