Завтра мне придётся доучить последние слова к диктанту.

Because придётся is used in an impersonal pattern:

кому? + придётся + infinitive

So:

• мне придётся = I will have to
• literally, it is closer to it will fall to me / it will be necessary for me

That is why Russian uses the dative мне, not nominative я.

Examples:

• Мне придётся работать. = I’ll have to work.
• Тебе придётся подождать. = You’ll have to wait.

Придётся is the future singular form of прийтись / приходиться.

In this construction, it means:

• to have to
• to be forced to
• to end up needing to

So мне придётся доучить... means I will have to finish learning...

It often suggests necessity because of circumstances, not just personal intention.

Compare:

• Я буду учить слова. = I will study the words.
• Мне придётся учить слова. = I will have to study the words.

The second one sounds more like obligation or pressure.

Доучить means to finish learning, to learn the rest, or to complete the memorization.

The prefix до- often adds the idea of reaching the end of something.

So:

• учить слова = to study/learn words
• выучить слова = to learn/memorize the words completely
• доучить слова = to finish learning the words, especially if part of the work was already done

In this sentence, доучить suggests that some words have probably already been studied, but the speaker still needs to finish the remaining ones.

They can be close, but the nuance is different.

• выучить = to learn something fully, from start to finish
• доучить = to finish learning what remains

So if you have not started yet, выучить is more natural:

• Мне надо выучить слова. = I need to learn the words.

If you already studied some of them and only need to complete the task:

• Мне надо доучить слова. = I need to finish learning the words.

In your sentence, доучить последние слова strongly suggests only the final remaining words are left.

Because доучить takes a direct object, and here the direct object is последние слова.

Since слова is an inanimate plural noun, its accusative plural looks the same as the nominative plural:

• nominative: последние слова
• accusative: последние слова

So the sentence uses the normal direct-object form.

If it were a masculine animate plural noun, the accusative would look different.

Not here.

In this sentence, последние слова means the last remaining words on a study list.

Because the context is к диктанту (for the dictation), it clearly refers to vocabulary that still needs to be learned.

So here it means something like:

• the last few words
• the remaining words

not someone’s final utterance.

К диктанту is к + dative.

The preposition к often means:

• toward
• for
• by the time of
• in preparation for

Here, слова к диктанту means words for the dictation or words to prepare for the dictation.

Forms:

• диктант = nominative
• к диктанту = dative after к

This is a very common pattern in school/study contexts:

• подготовиться к экзамену = to prepare for the exam
• вопросы к уроку = questions for the lesson
• слова к диктанту = words for the dictation

Sometimes для диктанта is possible in a broad sense, but к диктанту is more natural here.

The difference is roughly:

• для диктанта = for the dictation, intended for it
• к диктанту = for the dictation, in preparation for it

With schoolwork and preparation, Russian often prefers к:

• готовиться к диктанту
• слова к диктанту

So in this sentence, к диктанту sounds idiomatic and standard.

Putting Завтра first sets the time frame right away: Tomorrow...

Russian word order is flexible, and the first position often highlights what the speaker wants to focus on.

So:

• Завтра мне придётся доучить последние слова к диктанту. = Tomorrow, I’ll have to finish learning the last words for the dictation.

You could also say:

• Мне завтра придётся доучить последние слова к диктанту.

That is also correct, but the version with Завтра first sounds slightly more natural if the speaker is emphasizing when this will happen.

Because the construction with придётся is impersonal.

Russian does not say я придусь here. Instead it says:

• мне придётся = I will have to
• тебе придётся = you will have to
• нам придётся = we will have to

The person affected is shown in the dative case, not as a normal nominative subject.

So the sentence is complete without я.

The -сь is the reflexive ending, a short form of -ся.

The verb is прийтись, not just прийти.

That reflexive form is part of the dictionary form and gives the verb its idiomatic meaning in this construction: to have to / to be necessary due to circumstances.

So you should learn it as a whole expression:

• прийтись / приходиться + infinitive

Examples:

• Мне пришлось уйти. = I had to leave.
• Нам придётся ждать. = We’ll have to wait.

Прийтись is perfective, and придётся is its future form.

Russian often uses:

• a perfective verb to express a one-time future result
• another infinitive after it to say what action will have to be done

So:

• придётся = it will become necessary
• доучить = to finish learning

This makes sense because the speaker is talking about a specific future situation tomorrow.

Its imperfective partner is приходиться:

• Мне приходится много работать. = I have to work a lot / I often have to work a lot.

That version usually describes repeated or ongoing necessity.

Yes. That is a good translation too.

Possible English translations include:

• Tomorrow I’ll have to finish learning the last words for the dictation.
• Tomorrow I’ll need to finish learning the remaining words for the dictation.
• Tomorrow I’ll have to finish memorizing the last words for the dictation.

The exact English wording depends on how naturally you want to express:

• obligation: have to
• necessity: need to
• memorization focus: memorize

But grammatically, the Russian sentence strongly suggests necessity, not just a casual plan.

The main stress points are:

• За́втра
• мне
• придётся
• доучи́ть
• после́дние
• слова́
• к дикта́нту

A few useful notes:

• придётся has stress on -дё-
• доучить has stress on the last syllable: доучи́ть
• диктанту has stress on та́н

If you say the whole sentence naturally, it will sound roughly like:

За́втра мне придётся доучи́ть после́дние слова́ к дикта́нту.

Not in this sentence.

After придётся, when you mean a single completed future action, Russian normally uses the perfective infinitive:

• придётся доучить

Доучивать is imperfective and would usually be used in different contexts, for example repeated action or process:

• Мне приходится доучивать слова по вечерам. = I have to keep finishing off vocabulary in the evenings.

So for tomorrow I will have to finish learning, доучить is the correct choice.