Doing Things Together: The Preposition 's'
To talk about doing things with someone (accompaniment), use the preposition s (with) followed by a noun in the instrumental case.
For most masculine and neuter nouns, the singular instrumental ending is -om. For feminine nouns ending in -a, replace the -a with -om.
Using 'sa' for Pronunciation
If the following word begins with a hissing sound—specifically the letters s, š, z, or ž—the preposition changes from s to sa to make it easier to pronounce.
Soft Consonants and Consonant Endings
Not all nouns take the -om ending. If a masculine noun ends in a "soft" consonant (such as j, lj, nj, c, č, š, or ž), or if a neuter noun ends in -e, the instrumental ending is -em.
Finally, there is a special group of feminine nouns that end in a consonant rather than -a. In the singular instrumental case, these nouns take the ending -i. For example, the feminine word for salt (sol) becomes soli. Notice how this combines with the pronunciation rule for sa:
