How do I know when to use -тся or -ться in a verb

Question

The title pretty much says it all. It's a very common mistake which (unfortunately) even many native speakers make.

Is there a rule to unambiguously decide should I end this verb with -тся or -ться?

I suppose this is the purpose of private beta, to pre-populate the site with questions (and answers) that are likely to arise. — Sergio Tulentsev, Jun 13 '12 at 21:33
@bonomo http://blog.stackoverflow.com/2012/05/encyclopedia-stack-exchange/ — Philip Seyfi, Jun 13 '12 at 21:36
oh, I apologize, here are some ideas for questions you might want to consider adding here http://gramota.ru/, http://www.alphadictionary.com/rusgrammar/ — Trident D'Gao, Jun 13 '12 at 21:48
I agree about adding a link to http://gramota.ru/ to the FAQ. Who can edit it? — Philip Seyfi, Jun 13 '12 at 21:57

Philip Seyfi · Accepted Answer · 2012-06-14T12:57:18.960

19

There are four cases when you put ь in verb suffixes:

Infinitive: умывать(ся), беречь(ся).
Second person singular present or future tense: умываешь(ся), бережёшь(ся).
After all consonants except й and г (ляг(те)) with imperative mood: исправь(те).
Suffixes following a vowel: вернусь, вернитесь, вернулись, вернувшись.

In all other cases, there is no ь.

The best way is to ask a question... If it ends in т, it's тся, if in ть, then it's ться:

Я собираюсь - что сдела*ть*? - прогуляться.
Сейчас - что делае*т*? - строится новый район.
Все, что может - что дела*ть*? - портиться, обязательно - что сделае*т*? - испортится!

edited Jun 14 '12 at 12:57

answered Jun 13 '12 at 21:25

Philip Seyfi

score 5 · Answer 2 · answered Jun 13 '12 at 21:23

The key here is to ask a question that this verb answers.

If the question is "what is it doing?", then the ending should be -тся (делается, пишется, причесывается, ...)

If the question is "what to do?", then it's -ться (делаться, писаться, причесываться, ...)

score 4 · Answer 3 · answered Jun 18 '12 at 19:48

4

It's a big problem ;-) and there's whole site dedicated to that question: http://tsya.ru/

answered Jun 18 '12 at 19:48

kirilloid

Haha, nice website :) Although one could argue that this ought to be a comment rather than an answer. +1 anyway – Armen Tsirunyan Jun 18 '12 at 20:15
I suppose, the whole site deserves whole answer ;-) – kirilloid Jun 18 '12 at 20:19
i always consider these rules as a good tool to 'remember recapitulation technique' – Yurij73 Jun 19 '12 at 22:26

3 Answers3