Enumerations in Russian - is an "и" needed?

Question

When listing things in Russian using commas, do you use an "и" before the last thing, e.g. "столы, стулья и полки", or should it just be "столы, стулья, полки"?

I've seen some internet pages omitting the "и", but it's not explained anywhere, so I don't know why.

Answer 1

Both

столы, стулья, полки

and

столы, стулья и полки

are appropriate. The conjunction "и" (in Russian - "союз") before the last element marks it as the last element and logically completes the sentence.

Another option is logical pairing/binding, for example:

столы и стулья, полки и шкафы, серванты и лавки

This could be used to logically group item pairs, or to subscribe a long enumeration (lots of elements).

Answer 2

It's up to you to decide whether to use и or not. In colloquial speech, the rules aren't strict. But in written speech — especially in scientific works — they do exist.

If the last word in enumeration is added without the conjunction и, the chain is meant and perceived as unfinished and open for possible addition (in some cases, the phrases и так далее, и тому подобное, и прочее can be used). An example from a scientific text:

Инфекции могут подразделяться на антропонозы (полиомиелит, менинго- кокковая инфекция, вирусный гепатит и др.) и зоонозы (бешенство, бруцеллез, лептоспироз, туляремия и пр.).

Enumeration is considered finished when the last word is linked with the conjunction и. The conjunction shows that the list is complete, exhaustive, and doesn't require additional information.

Музыкальные звуки различаются по силе, высоте и тембру.

Answer 3

The last и isn't required, but its usage is pretty natural in the most cases.

Answer 4

There's another one type of enumeration (not listed in previous answers). It's used when you want to emphasize that all items in the list have a certain property:

В этой комнате и столы, и стулья, и полки, и шкафы были выкрашены в белый цвет.

Here, you put the conjunction и before each word and a comma between the words in the list.

Answer 5

In addition to the other answers, it's worth pointing out that when the conjunction и is used, the implied meaning is that the list is complete, i.e. you've listed everything that's relevant:

Столы, стулья и полки [and nothing else]

When the conjunction is omitted, the implied meaning is that there may be other relevant items, but you don't really want/need to list them all, so you've only listed a few:

Столы, стулья, полки [and maybe other items of furniture]