Ми чекаємо тринадцять хвилин.

Yes. Ukrainian often drops subject pronouns because the verb ending already shows who is doing the action.

• чекаємо already means we wait / we are waiting
• So Чекаємо тринадцять хвилин is perfectly natural

Keeping ми is also fine. It can make the sentence:

• a little clearer
• a little more explicit
• or slightly emphatic, especially if you are contrasting we with someone else

Чекаємо is the 1st person plural present tense form of чекати.

So:

• чекати = the infinitive, to wait
• чекаємо = we wait / we are waiting

The ending -ємо tells you it is we.

Also, чекати is an imperfective verb, so it is the normal choice for an ongoing or repeated action.

It can mean either one. Ukrainian does not usually separate these two ideas the way English does.

So Ми чекаємо тринадцять хвилин can correspond to:

• We wait thirteen minutes in the right context
• We are waiting for thirteen minutes
• and very often, in natural English, We have been waiting for thirteen minutes

Context tells you which English version fits best.

Yes, very often.

Ukrainian commonly uses the present tense for an action that started in the past and is still continuing now, where English would use have been waiting.

So:

• Ми чекаємо тринадцять хвилин can have that meaning
• Ми вже чекаємо тринадцять хвилин makes that idea even clearer

The word вже often helps show already / for this long by now.

Because Ukrainian usually expresses duration without a preposition.

In English you say:

• for thirteen minutes

In Ukrainian you normally just say:

• тринадцять хвилин

So after many verbs, a time duration appears directly:

• чекати три години = to wait for three hours
• працювати два дні = to work for two days

That is completely normal Ukrainian structure.

Because after 13, the noun takes the genitive plural form.

Here:

• хвилина = minute
• хвилин = genitive plural

A very important number rule in Ukrainian is:

• after 2, 3, 4 → usually хвилини
• after 5 and up → usually хвилин
• and 11, 12, 13, 14 also use хвилин

So:

• три хвилини
• чотири хвилини
• п’ять хвилин
• тринадцять хвилин

Even though тринадцять contains три, it behaves like the 11–14 group, not like plain 3.

Yes, and that is a great thing to notice.

When чекати means waiting for someone or something, Ukrainian often uses:

• чекати на когось / на щось
• or sometimes чекати когось / чогось

But in this sentence, тринадцять хвилин is not the thing being waited for. It expresses how long the waiting lasts.

So compare:

• Ми чекаємо на автобус. = We are waiting for the bus.
• Ми чекаємо тринадцять хвилин. = We have been waiting for thirteen minutes.

Those are two different grammatical roles.

Yes. Ukrainian word order is fairly flexible.

The most neutral order here is:

• Ми чекаємо тринадцять хвилин.

But you can move things for emphasis:

• Тринадцять хвилин ми чекаємо. = emphasizes the duration
• Чекаємо тринадцять хвилин. = natural conversational version without ми

So the basic meaning stays the same, but the focus can shift.

A useful stress-marked version is:

Ми чека́ємо трина́дцять хвили́н.

A rough English-friendly guide is:

my cheh-KA-ye-mo try-NA-dtsyat khvy-LIN

A few notes:

• ч sounds like ch in church
• х sounds like the ch in Scottish loch or German Bach
• и is not the same as English ee; it is a shorter, more central vowel
• the stress matters, especially in чека́ємо and хвили́н

Because Ukrainian has no articles.

So Ukrainian does not have direct equivalents of English a and the in ordinary sentences. Whether something is definite or indefinite is understood from context.

That is why Ми чекаємо тринадцять хвилин needs no extra word before тринадцять хвилин.