Verbs of descent and gathering (с-, со-)

Adding the prefix с- (or со-) to a verb of motion adds one of two meanings: moving down or off a surface, or (if the verb is reflexive) coming together from different directions.

Converging by Vehicle: съезжаться / съехаться

Adding the prefix с- and the reflexive suffix -ся to verbs for going by vehicle (ездить and ехать) creates the meaning "to converge" or "gather." You will often see these used for mass gatherings like a festival (фестиваль) or fair (ярмарка).

Because the prefix ends in a consonant and the root starts with the letter е, a hard sign (ъ) is inserted to separate the sounds.

Use the imperfective съезжаться for regular occurrences or actions in progress:

Use the perfective съехаться (which conjugates like ехать) for a completed gathering or a future result:

Going Down: спускаться / спуститься

To express the general idea of descending—like going down a mountain or walking down a staircase—use the verbs спускаться (imperfective) and спуститься (perfective).

Stepping Off: сходить / сойти

For walking down, getting off a vehicle, or stepping off a raised surface, use сходить (imperfective) and сойти (perfective).

The perfective prefix becomes со- to make pronunciation easier. These verbs usually pair with the preposition с (or со) plus the Genitive case, meaning "off of" or "down from":

Coming Together on Foot: сходиться / сойтись

Adding the reflexive suffix -ся / -сь to these verbs shifts the meaning to "converging" or "coming together." This applies to crowds or even abstract things like roads.

The past tense of the perfective сойтись is irregular, like the base verb идти. A common plural past tense form is сошлись.

Here is how you might describe people converging for an event like a parade (парад):