Не спеши, иначе прольёшь кофе.

In Russian, the subject is often omitted when it is obvious from the verb form.

Here, не спеши is an imperative form meaning don’t hurry, and it clearly implies you in the singular, informal sense: ты.

So the full idea is:

• (Ты) не спеши, иначе прольёшь кофе.

Russian usually leaves ты out unless it is needed for emphasis.

Because не спеши is a command or instruction, while не спешишь is a statement.

• не спеши = don’t hurry / take your time
• не спешишь = you are not hurrying

So in this sentence, the speaker is telling someone what to do, which requires the imperative.

Спеши is the imperative singular informal form of спешить.

That means it is used when speaking to:

• one person
• in an informal way

Compare:

• не спеши = don’t hurry (to one person, informal)
• не спешите = don’t hurry (to several people, or one person politely/formally)

That is the normal way to make a negative command in Russian.

So:

• спеши = hurry
• не спеши = don’t hurry

This is very similar to English in meaning, even though the grammar is different.

Russian often uses the imperfective in negative commands when the meaning is don’t do this in general or avoid this action.

So не спеши means something like:

• don’t be in a hurry
• don’t rush
• take your time

A perfective form would sound different and usually would not be the natural choice here.

Иначе means otherwise, or else, or if not.

In this sentence, it introduces the consequence of not following the advice:

• Не спеши, иначе прольёшь кофе.
• Don’t hurry, otherwise you’ll spill the coffee.

It is a very common word for warnings like this.

Because Russian normally separates clauses like these with a comma.

Here you have:

• Не спеши = first clause
• иначе прольёшь кофе = second clause

The comma marks the break between the warning and its consequence.

Прольёшь is the 2nd person singular future form of пролить, a perfective verb.

It means you will spill.

So:

• пролить = to spill
• прольёшь = you will spill

Because it is addressed to you and refers to a likely future result, Russian uses this form.

Russian expresses this warning as a future consequence:

• иначе прольёшь кофе = otherwise you will spill the coffee

That is natural in Russian. English can also say otherwise you’ll spill your coffee, so the structure is quite close.

Because that is the correct spelling of this form of пролить.

A useful rule: ё is always stressed.

So прольёшь is pronounced with stress on ё.

In many printed texts, Russians sometimes write е instead of ё, so you may also see:

• прольешь

But it still means the same word, and it is still pronounced with ё.

Кофе is a special noun because it is usually indeclinable, meaning its form does not change across cases.

Here it is the direct object, so it is in the accusative case, but the word still looks the same:

• кофе = coffee
• прольёшь кофе = you will spill coffee / the coffee

So yes, it is an object, but the form does not change.

It is in the accusative case, because it is the direct object of прольёшь.

You are spilling what?

• кофе

Even though the word does not change in form, its grammatical role is still accusative.

Traditionally, кофе is treated as masculine in standard Russian:

• горячий кофе
• вкусный кофе

However, in everyday speech some speakers may use neuter, especially colloquially. For learners, it is best to remember that the standard norm is masculine.

In this sentence, that does not affect the form кофе, since the noun is indeclinable.

Yes, you could say:

• Ты не спеши, иначе прольёшь кофе.

But adding ты usually gives extra emphasis, contrast, or a more conversational tone. In most situations, leaving it out is more natural.

It is informal, because both verbs are singular forms used with ты:

• не spеши
• прольёшь

If you wanted to say the same thing politely or to more than one person, you would say:

• Не спешите, иначе прольёте кофе.

Yes. Russian has no articles, so кофе can mean:

• coffee
• the coffee
• sometimes some coffee

The exact meaning depends on context. In this sentence, English will often use the coffee or your coffee, but Russian simply says кофе.

Yes, Russian word order is fairly flexible.

The version here:

• Не спеши, иначе прольёшь кофе

is the most neutral and natural order.

You could change the order for emphasis, but it may sound less neutral. For example:

• Иначе прольёшь кофе, не спеши would sound unusual in most contexts.
• Кофе прольёшь could emphasize coffee.

For learners, the original order is the best one to remember.