Если я не успеваю дочитать статью вечером, я дочитаю её утром.

This is very common in Russian conditional sentences.

After если (if), Russian often uses the present tense to talk about a future condition:

• Если я не успеваю... = If I don’t manage / if I’m not able in time...
• ...я дочитаю её утром. = ...I’ll finish it in the morning.

So Russian does not need a future form in both parts the way English sometimes seems to. The present tense in the если clause can refer to a future situation.

Успеваю comes from успевать / успеть, which means:

• to be in time
• to manage to do something before it’s too late
• to have enough time to do something

So не успеваю дочитать статью вечером means more than just I don’t finish the article in the evening. It specifically means:

• I don’t manage to finish it in time
• I run out of time before finishing it

That idea of time pressure is important.

Because дочитать means to finish reading, to read to the end.

Compare:

• читать статью = to read an article / to be reading an article
• дочитать статью = to finish reading the article

Since the sentence is about whether the article gets completed, Russian uses дочитать, not just читать.

The prefix до- often adds the idea of:

• reaching the end
• finishing something
• doing something to completion

So:

• читать = to read
• дочитать = to finish reading

It is similar to the difference between:

• to read
• to read through / finish reading

They are the same verb, but in different forms:

• дочитать = infinitive, to finish reading
• дочитаю = 1st person singular future, I will finish reading

So:

• не успеваю дочитать = I don’t manage to finish reading
• я дочитаю её утром = I’ll finish it in the morning

Because дочитать is a perfective verb, its simple future form is дочитаю.

Because дочитать is perfective.

In Russian:

• imperfective verbs form the future with быть
  • infinitive
    
    • буду читать = I will be reading / I will read
• perfective verbs form the future with one simple form
  
  • дочитаю = I will finish reading

Since the meaning here is completion, the perfective form is the natural choice.

Because статья is the direct object, so it goes into the accusative case.

• dictionary form: статья
• accusative singular: статью

This is a regular pattern for many feminine nouns ending in -я:

• неделя → неделю
• идея → идею
• статья → статью

So дочитать статью means to finish reading the article.

Because Russian usually avoids repeating the noun unnecessarily, just like English:

• я дочитаю статью утром = I’ll finish the article in the morning
• я дочитаю её утром = I’ll finish it in the morning

Here её means it, referring to статью.

Its form is the same here as the accusative/genitive feminine singular pronoun:

• её = her / it

In this sentence it clearly means it, because it refers to the article.

Russian often uses certain time expressions without a preposition, especially parts of the day in the instrumental case:

• утром = in the morning
• днём = in the daytime / during the day
• вечером = in the evening
• ночью = at night

So:

• вечером = literally something like by evening-time
• утром = in the morning

This is just a normal Russian time expression pattern.

Because the sentence has two clauses:

• Если я не успеваю дочитать статью вечером
• я дочитаю её утром

In Russian, a subordinate clause introduced by если is separated by a comma from the main clause.

So the comma is required.

Yes. Russian word order is flexible, and the meaning would stay basically the same.

For example, you could also say:

• Если я вечером не успеваю дочитать статью, я дочитаю её утром.
• Я дочитаю её утром, если я не успеваю дочитать статью вечером.

The original version is very natural. Word order changes usually affect:

• emphasis
• rhythm
• what sounds more natural in context

But not the basic meaning.

They are similar, but not identical.

• не успеваю дочитать = I don’t have time to finish reading
• не могу дочитать = I can’t finish reading

Не могу is broader. It could mean:

• I’m too tired
• it’s too difficult
• something prevents me

Не успеваю specifically points to lack of time.

So in this sentence, не успеваю is the better choice.

It can sound like either, depending on context.

It may mean:

1. a likely future situation

   • If I don’t manage to finish the article this evening, I’ll finish it in the morning.

2. a general pattern

   • If I don’t manage to finish an article in the evening, I finish it in the morning.

But because the second clause uses дочитаю (future perfective), the most natural reading here is a specific future situation.

If you wanted a more habitual meaning, Russian would often use different context or different tense choices.