Этот результат оказался неудачным, поэтому мне придётся всё повторить.

Оказался is the past tense of оказаться. In this sentence, it means turned out to be.

So:

• Этот результат оказался неудачным = This result turned out to be unsuccessful / bad

This is a very common Russian way to say that something ended up being a certain way.

A useful comparison:

• быть = to be
• оказаться = to turn out to be

So оказался adds the idea of an outcome or discovery, not just a simple description.

Because it agrees with результат, which is:

• masculine
• singular
• the subject of the clause

So the past tense form must match:

• результат оказался
• not оказалась
• not оказалось

Russian past tense verbs agree in gender and number with the subject.

After verbs like оказаться when they mean to turn out to be, Russian usually puts the predicate noun or adjective in the instrumental case.

So:

• результат оказался неудачным
• literally: the result turned out unsuccessful

That is why you get:

• неудачный → nominative
• неудачным → instrumental masculine singular

This pattern is very common with verbs such as:

• быть in some contexts
• стать = to become
• оказаться = to turn out to be
• являться = to be, to constitute

Examples:

• Он стал врачом. = He became a doctor.
• Она оказалась правой. = She turned out to be right.

Неудачный usually means something like:

• unsuccessful
• unsatisfactory
• bad
• not successful

It does not usually mean unlucky in the sense of a person having bad luck.

So неудачный результат is better understood as:

• a poor result
• an unsuccessful result
• a result that didn’t come out well

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

It connects the first idea to the consequence:

• Этот результат оказался неудачным = This result turned out badly
• поэтому мне придётся всё повторить = so I’ll have to repeat everything

The comma appears because Russian is joining two clauses here:

1. Этот результат оказался неудачным
2. поэтому мне придётся всё повторить

So the comma works much like in English before so or therefore.

Придётся is the future tense of прийтись, used here in an impersonal meaning:

• придётся = it will be necessary / one will have to
• мне придётся = I will have to

This is a very common Russian way to say have to.

Compare:

• Мне придётся уйти. = I’ll have to leave.
• Нам придётся подождать. = We’ll have to wait.

It often implies that circumstances make something necessary, rather than the speaker personally choosing it.

Because this construction uses the dative case for the person affected.

So:

• мне = to me / for me
• придётся = it will be necessary

Together, мне придётся idiomatically means I will have to.

This is a standard Russian pattern:

• мне нужно = I need
• мне надо = I need / I have to
• мне придётся = I will have to

English uses a nominative subject (I), but Russian often uses a dative experiencer in these impersonal constructions.

Because повторить is perfective, and here it means to repeat everything once, as a complete action.

• повторить = to repeat / redo completely, one time
• повторять = to be repeating / to repeat regularly / to repeat as a process

In this sentence, the speaker means:

• the result was bad
• so they will have to redo the whole thing

That calls for the perfective infinitive повторить.

If you used повторять, it would sound more like an ongoing or habitual process, which does not fit as well here.

Всё here means everything.

So:

• всё повторить = to repeat everything

This is different from все, which usually means all or everyone, depending on context.

Compare:

• всё = everything
• все = all people / everyone / all items in a plural group

Also, the letter ё matters here:

• всё and все are different words

In many Russian texts, ё is often written as е, so you may sometimes see все where the intended pronunciation is actually всё. That can be confusing for learners.

No, Russian word order is fairly flexible, but this version is natural and neutral.

The sentence as written:

• Этот результат оказался неудачным, поэтому мне придётся всё повторить.

sounds smooth and standard.

Why this order works well:

• Этот результат introduces the topic
• оказался неудачным gives the evaluation
• поэтому introduces the consequence
• мне придётся всё повторить states what must be done

You could move some parts around for emphasis, but the original order is probably the most natural choice for everyday written or spoken Russian.

Yes, there is a small nuance.

• мне придётся = I’ll have to because circumstances make it necessary
• я должен буду = I will have to / I will be obliged to, often sounding more personal, deliberate, or obligation-focused

In this sentence, мне придётся is very natural because the bad result leads to a necessary consequence: now the speaker has to redo everything.

So придётся fits the logic of the situation leaves me no choice very well.