When writing in language 1 about the features of language 2, some stylistic conventions can help clarify whether a particular piece of text is L1 or L2, whether it is a gloss or a translation, and whether it is in the language's orthography, or is a phonemic or phonetic transcription.
The following conventions are often used by linguists and lexicographers, and are recommended in such cases:
If a text is describing more than one foreign language, and context does not make it obvious which language is associated with a gloss or transcription, the 2- or 3-letter ISO 639 code for the language is appended, in parentheses, as in: (es) for Spanish.
When writing an L2 word or phrase in L1, if the word is written in its original script or orthography, it is usually presented in italics or standard font without additional punctuation. Discussing how the English word "cat" is translated into Russian, text might use the Russian word кошка.
Phonemic transcriptions, which give rough approximations without worrying about minor accent variations, are shown between slashes /.../. For example, the phonemic transcription of the English word "cat" would be /kæt/. IPA is used between the slashes.
Phonetic transcriptions, which provide more detail on a specific pronunciation, are shown between square brackets [...]. IPA is used between the brackets. For example, the detailed phonetic transcription of "cat" might be [kʰæt], indicating the aspiration of the initial /k/.
Glosses, which provide the meaning of a word, phrase, or sentence in L2, directly follow the word or phrase that they explain. They are enclosed in single quotes and may be preceded by an em dash for clarity. For example, text discussing a conversation about pets overhead in Madrid might say:
I heard her say gato — 'cat'.
This same technique can be used with full sentences:
El gato está en la casa — 'The cat is in the house'.
For more complex examples, linguists use interlinear glossing. This method provides a word-for-word or morpheme-by-morpheme translation aligned vertically:
El gato está en la casa
the cat is in the house
Names of languages and technical terms are italicized when they first appear in a text. For example, phonology, syntax, Mandarin Chinese.