Breakdown of Došli smo s iskusnim vodičem.
biti
to be (sam, si, je)
doći
to come, to arrive
iskusan
experienced
s
with
Questions & Answers about Došli smo s iskusnim vodičem.
Why does the adjective end in -im in iskusnim vodičem?
Because it comes after the preposition s (with), the whole phrase must be in the instrumental case. To match the masculine noun vodičem (guide), the adjective iskusan (experienced) changes to the instrumental too. For masculine and neuter adjectives in the singular instrumental case, the ending is always -im, giving us iskusnim.
Why does the noun vodič become vodičem instead of vodičom?
Most masculine nouns add -om in the singular instrumental case (for example, s bratom). However, there is a spelling rule: if the noun ends in a "soft" consonant like č, ć, š, ž, j, lj, or nj, the ending changes to -em. Since vodič ends in č, it becomes vodičem.
Why do we use the short preposition s here instead of sa?
Both s and sa mean "with" and require the instrumental case. You use the shorter s most of the time. The longer sa is only needed when the next word starts with a hissing sound that would make s hard to pronounce (like s, z, š, or ž). Since the next word here (iskusnim) starts with an i, the plain s is perfectly easy to say.