Сегодня мне некогда долго готовить, поэтому я просто съел банан и выпил кефир.

Мне некогда is a very common Russian expression meaning I have no time or I’m too busy.

Literally, it is closer to To me, there is no time. Russian often uses this kind of impersonal structure instead of saying something like I do not have time.

So:

• мне = to me
• некогда = there is no time / no time available

This is why there is no ordinary verb like have in the sentence. Russian often expresses possession or availability without using a direct equivalent of English to have.

Because некогда is used with the dative case.

In Russian, some impersonal expressions describe a person’s state or situation using the dative, not the nominative. So:

• я = I (nominative)
• мне = to me / for me (dative)

With некогда, Russian treats the idea as it is not possible for me because there is no time, so the person goes into the dative:

• Мне некогда = I have no time

Other similar expressions also use the dative, for example:

• мне холодно = I am cold
• мне скучно = I am bored

After некогда, Russian usually uses an infinitive to say there is no time to do something.

So:

• мне некогда готовить = I have no time to cook

This works just like English to cook after no time.

In this sentence, готовить is the action that there is no time for.

Долго means for a long time.

So:

• долго готовить = to cook for a long time
• or more naturally in English here: to spend a long time cooking

The word долго modifies готовить and tells you the cooking would take a long time.

So the first part means roughly:

• Today I don’t have time to cook for long
• or Today I don’t have time to spend long cooking

Here готовить is the more natural choice because the focus is on the process of cooking, especially with долго.

• готовить is imperfective: it describes the activity/process
• приготовить is perfective: it focuses on completing/preparing something

Since долго emphasizes duration, Russian normally prefers the imperfective:

• долго готовить = to cook for a long time

Using a perfective verb here would sound much less natural, because perfective verbs usually focus on the result, not the duration of the process.

Поэтому means therefore, so, or that’s why.

In this sentence it connects the two ideas:

• Today I don’t have time to cook for long
• so I just ate a banana and drank kefir

Russian often places поэтому near the start of the second clause:

• ..., поэтому я просто съел банан...

That is very natural.

You may also hear slightly different word orders in other sentences, but this placement is one of the most common.

Because съел and выпил are perfective past-tense verbs, and they show completed actions.

• есть → съесть = to eat → to eat up / eat completely
• пить → выпить = to drink → to drink up / drink

In this sentence, the speaker is talking about specific finished actions:

• he ate a banana
• he drank kefir

So perfective verbs fit well.

Compare:

• я ел банан = I was eating / I ate (process, not emphasizing completion)
• я съел банан = I ate the banana / I finished eating a banana

And:

• я пил кефир = I was drinking kefir
• я выпил кефир = I drank the kefir / I finished drinking kefir

They show that the speaker is masculine singular.

In Russian past tense, verbs agree with gender and number:

• masculine: съел, выпил
• feminine: съела, выпила
• neuter: съело, выпило
• plural: съели, выпили

So this sentence was spoken by a man, or at least by a speaker using masculine forms.

If the speaker were female, it would be:

• Сегодня мне некогда долго готовить, поэтому я просто съела банан и выпила кефир.

The hard sign ъ appears because the prefix с- is attached to a root beginning with е.

So the spelling is:

• с- + ел → съел

The hard sign separates the prefix from the following vowel and signals that the е is pronounced with a y-like onset, roughly like s-yel.

This is a standard spelling rule in Russian after certain prefixes before е, ё, ю, я.

You see the same kind of thing in words like:

• объём
• подъезд
• съесть

They are in the accusative, but for inanimate masculine singular nouns, the accusative form is usually the same as the nominative.

So:

• банан = nominative

• банан = accusative

• кефир = nominative
• кефир = accusative

That is why there is no visible ending change.

If the noun were animate masculine, you would often see a different form. For example:

• я вижу брата = I see my brother

Here the accusative differs from the nominative брат.

Yes, in English the most natural translation would often be some kefir or simply kefir, depending on context.

Russian has no articles like a, an, or the, so nouns often appear without anything extra.

Also, with drinks and foods, Russian very often uses the bare noun when the meaning is general or understood from context:

• выпил кефир = drank kefir / drank some kefir

It does not necessarily mean he drank all kefir in existence or even a specifically marked container unless the context makes that clear.

Просто here means just or simply.

It gives the idea that the speaker chose an easy, minimal solution because there was no time:

• я просто съел банан и выпил кефир
• I just ate a banana and drank kefir

So просто adds the nuance of nothing elaborate or nothing special.

The sentence’s word order is natural, but Russian word order is fairly flexible.

This version is neutral and clear:

• Сегодня мне некогда долго готовить, поэтому я просто съел банан и выпил кефир.

Some parts could move for emphasis. For example:

• Сегодня мне некогда долго готовить, поэтому просто я съел банан и выпил кефир.

But that sounds less natural in most contexts.

Or:

• Сегодня мне некогда долго готовить, поэтому банан я просто съел и выпил кефир.

This puts extra emphasis on банан, which is unusual unless you are contrasting it with something else.

So while Russian allows movement, the original order is probably the best default for a learner.

Not always. Russian often drops subject pronouns when the meaning is clear from the verb form or context.

So you could say:

• Сегодня мне некогда долго готовить, поэтому просто съел банан и выпил кефир.

This is possible in conversation, especially if it is already obvious who is speaking.

However, including я is completely natural and often clearer for learners:

• ..., поэтому я просто съел банан и выпил кефир.

So the version with я is a good standard form.

Because поэтому connects two clauses here.

The first clause is:

• Сегодня мне некогда долго готовить

The second clause is:

• поэтому я просто съел банан и выпил кефир

In standard Russian punctuation, these are separated by a comma.

So the comma works much like in English sentences with so, therefore, or that’s why joining two parts.