Learn Hardcore Russian: Иногда я ошибаюсь, когда спешу. - Sometimes I make mistakes when I am in a hurry.

The ending -сь (or -ся) makes the verb reflexive. With ошибаться, it does not mean you literally do something to yourself; instead, it forms a verb whose meaning is simply “to be wrong / to make a mistake.”

So:

ошибаться = to be mistaken, to make mistakes (imperfective)
я ошибаюсь = I’m wrong / I make mistakes

There is no non‑reflexive verb ошибать with the same meaning, so you always need the -ся / -сь part with this verb.

Why do we use ошибаюсь (imperfective) here and not the perfective ошибусь?

In Russian, the imperfective aspect is used for:

repeated / habitual actions
general truths

The sentence describes a general pattern: “Sometimes I make mistakes when I hurry.” That’s exactly a habitual situation, so imperfective ошибаюсь is natural.

The perfective ошибиться (future: я ошибусь) is for a single, completed mistake:

Осторожно, не ошибись. – Be careful, don’t make a mistake (this time).
Я однажды сильно ошибся. – I made a big mistake once.

Using я ошибусь in this sentence would sound like you are predicting a specific future mistake, not talking about a general tendency.

Why is there a comma before когда? Is it mandatory?

Yes, the comma is required here.

In Russian, когда introduces a subordinate clause of time. You have:

Main clause: Иногда я ошибаюсь
Subordinate clause: когда спешу

Russian punctuation rules say you must put a comma between a main clause and a subordinate clause introduced by words like когда, если, потому что, etc.

So the comma in Иногда я ошибаюсь, когда спешу. is not optional; it’s standard grammar.

Why is there no я in когда спешу? Can I say когда я спешу instead?

The subject я is understood and therefore omitted. In Russian, if two clauses share the same subject and it is clear from context, it’s common (and natural) to drop the subject pronoun in the second clause:

Иногда я ошибаюсь, когда спешу.
Literally: “Sometimes I make mistakes, when (I) hurry.”

You can say:

Иногда я ошибаюсь, когда я спешу.

This is grammatically correct, but it sounds a bit heavier and is only used if you want to emphasise that it is exactly when I hurry (not someone else, not some other condition) that I make mistakes. In everyday speech, the shorter когда спешу is more natural.

Does когда here mean “when” or “whenever”? How should I understand it?

In English, we’d usually translate the sentence as:

“Sometimes I make mistakes when I’m in a hurry.”
or
“Sometimes I make mistakes whenever I’m in a hurry.”

Russian often uses present tense + когда to express a general, repeated situation. So когда спешу really has the idea of “whenever I happen to be in a hurry”, not one specific occasion. The context—plus the word иногда (“sometimes”)—makes it clearly habitual.

Why is спешу in the present tense? In English I might say “when I’m in a hurry” or “when I hurry” – how does this match?

Russian uses the present tense in both clauses to describe a habitual pattern:

я ошибаюсь – I (generally) make mistakes
когда спешу – when(ever) I’m in a hurry / whenever I hurry

The Russian present tense here is equivalent to the English present simple or “when I’m in a hurry” in a general sense.

To talk about the future, Russian can still use present after когда:

Когда спешу, я часто ошибаюсь. – Whenever I hurry, I often make mistakes.
Когда спешу, я ошибаюсь. – When I’m in a hurry, I make mistakes.

So the form спешу is present tense, but the meaning is generic / habitual, not “right now” only.

Can I say Иногда я делаю ошибки, когда спешу instead of Иногда я ошибаюсь? What’s the difference?

Yes, you can say:

Иногда я делаю ошибки, когда спешу.

This is correct and natural. The difference is subtle:

я ошибаюсь – literally “I make a mistake / I’m wrong,” more compact and idiomatic.
я делаю ошибки – literally “I make mistakes” (plural); slightly more explicit and a bit more “schoolbook” in feel.

In many contexts they are interchangeable, but ошибаться is the more typical verb for “being wrong / making mistakes” in a general way. Your original sentence with ошибаюсь sounds very natural.

What is the infinitive and basic meaning of спешу?

The infinitive is спешить.

Basic meanings relevant here:

спешить = to hurry, to be in a hurry, to be rushing

So:

я спешу – I’m in a hurry / I’m hurrying
когда спешу – when(ever) I’m in a hurry / when I rush

It’s an intransitive verb in this usage (no direct object: you don’t “hurry something,” you just hurry).

Can I use торопиться instead of спешить? What’s the difference between спешу and тороплюсь?

Yes, you can say:

Иногда я ошибаюсь, когда тороплюсь.

Both are idiomatic. Nuances:

спешить (я спешу) – to hurry, to be in a hurry; fairly neutral and common.
торопиться (я тороплюсь) – also “to hurry / to rush,” often with a stronger feeling of rushing, not taking time, being pressed for time.

In this sentence, both work very well. спешу might feel a bit more neutral; тороплюсь can slightly underline the idea of “rushing and therefore being careless.”

Can I change the word order, for example: Я иногда ошибаюсь, когда спешу? Does it change the meaning?

Yes, you can change the word order:

Иногда я ошибаюсь, когда спешу.
Я иногда ошибаюсь, когда спешу.

Both are correct and mean the same thing. The nuance:

Иногда я ошибаюсь... – puts a bit more emphasis on иногда (“sometimes”).
Я иногда ошибаюсь... – starts with я, which is more neutral word order in casual speech.

The difference is very small; both versions are natural and commonly used.

Is this sentence gender‑specific? Would a woman have to change anything?

Nothing changes.

Both verbs are in the present tense:

я ошибаюсь
(я) спешу

Present tense verb forms in Russian do not change with the gender of the speaker. They only change with person and number (я, ты, он/она, мы, вы, они). So a man and a woman would say this sentence in exactly the same way.

How is иногда я ошибаюсь, когда спешу pronounced and where is the stress?

Stresses (marked with capitals for clarity):

иногда́ – ee-nag-DA
я – ya
ошиба́юсь – a-shi-BA-yusʹ
когда́ – kag-DA
спешу́ – spe-SHOO

Connected speech, roughly:
ee-nag-DA ya a-shi-BA-yus, kag-DA spe-SHOO.

Each content word here has stress on the last syllable.