Мне трудно произносить длинные слова быстро, но я могу произнести их правильно, если не спешу.

Russian often uses an impersonal construction here:

• мне = to me / for me in the dative case
• трудно = difficult / hard

So Мне трудно произносить... literally means something like To me, it is difficult to pronounce...

This is a very common Russian pattern:

• Мне трудно понять. = It is hard for me to understand.
• Ему легко читать. = It is easy for him to read.
• Нам интересно слушать. = It is interesting for us to listen.

English usually uses I as the subject, but Russian often uses dative + a predicative word like трудно, легко, интересно, нужно, можно, нельзя.

This is a classic Russian aspect pair:

• произносить = imperfective
• произнести = perfective

In this sentence, they are used for different reasons.

1. Мне трудно произносить длинные слова быстро

Here произносить is imperfective because it describes a general ability/problem or an ongoing kind of action:

• It is hard for me to pronounce long words quickly

The focus is not on one completed result, but on the activity in general.

2. но я могу произнести их правильно

Here произнести is perfective because it means to pronounce them successfully / correctly as a completed act

• but I can pronounce them correctly

The idea is: I am able to achieve the result.

A helpful way to think about it:

• imperfective = the process, habit, or general activity
• perfective = one completed successful instance or result

After мочь, either aspect can appear depending on meaning, but here perfective makes good sense because the speaker means I can manage to pronounce them correctly.

Because слова is the direct object of произносить.

The dictionary form is:

• длинное слово = a long word

In the plural:

• длинные слова = long words

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

• nominative plural: длинные слова
• accusative plural: длинные слова

So although it looks like the subject form, here it is actually the object form.

If the noun were animate, the accusative plural would often look different.

Because Russian, like English, often uses a pronoun to avoid repetition.

• слова = words
• их = them

So:

• я могу произнести их правильно
  = I can pronounce them correctly

Here их is the accusative plural form of the pronoun они for inanimate plural objects, and it refers back to длинные слова.

Russian could repeat слова, but using их sounds more natural and less repetitive.

Because these words describe how the action is done, so they are adverbs.

• быстрый = fast, quick → быстро = quickly
• правильный = correct → правильно = correctly

They modify the verbs:

• произносить быстро = to pronounce quickly
• произнести правильно = to pronounce correctly

This is just like English:

• quick → quickly
• correct → correctly

Although Russian adverbs do not always correspond perfectly to English -ly, here the function is the same.

Russian often omits subject pronouns when the verb ending already shows who is doing the action.

In я могу произнести

The speaker uses я for clarity and contrast:

• ..., но я могу... = ..., but I can...

The я helps emphasize the contrast with the first part.

In если не спешу

The verb спешу already clearly means I hurry / I am in a hurry, because the ending -у marks first person singular.

So если не спешу naturally means:

• if I am not hurrying
• if I do not rush

Russian often drops я when it is obvious from context.

Спешить means to hurry, to be in a hurry, or to rush.

So:

• если не спешу = if I am not hurrying
• more naturally in English: if I do not rush

This does not just mean slowly. It specifically means the speaker is not under time pressure and is taking their time.

That nuance matters:

• медленно = slowly
• не спешу = I am not rushing / I am taking my time

So the sentence means not simply that the person speaks slowly, but that they can pronounce the words correctly when they do not rush.

Russian word order is more flexible than English word order. In neutral speech, adverbs like правильно often come after the object:

• произнести их правильно

This sounds natural and clear.

Other orders are possible too, depending on emphasis:

• правильно произнести их
• их правильно произнести

But the original order is a very normal neutral choice.

In general, Russian word order is shaped more by information structure and emphasis than by strict rules like in English.

Yes. Russian allows some flexibility:

• Мне трудно произносить длинные слова быстро.
• Мне трудно быстро произносить длинные слова.

Both are possible.

The difference is subtle:

• произносить длинные слова быстро focuses a bit more on the final adverb quickly
• быстро произносить длинные слова groups quickly pronounce more tightly as one idea

In many everyday contexts, both would sound fine. The original sentence is completely natural.

Yes, если basically means if.

In this sentence:

• если не спешу = if I do not rush

It introduces a condition: the speaker can pronounce the words correctly on the condition that they are not hurrying.

Russian uses если in very much the same way English uses if:

• Если у меня есть время, я читаю. = If I have time, I read.
• Если не спешишь, ошибок меньше. = If you do not rush, there are fewer mistakes.

So here the structure is very straightforward.

It has three main parts:

1. Мне трудно произносить длинные слова быстро
   = It is hard for me to pronounce long words quickly

2. но я могу произнести их правильно
   = but I can pronounce them correctly

3. если не спешу
   = if I do not rush

So the full logic is:

• Fast pronunciation of long words is difficult for me
• but correct pronunciation is possible
• when I am not rushing

This is a nice example of how Russian combines:

• an impersonal construction: мне трудно
• aspect contrast: произносить / произнести
• a conditional clause: если не спешу

Yes. Но is the normal everyday word for but.

• но = neutral, common, conversational
• однако = more formal, literary, or emphatic in many contexts

This sentence is simple and natural, so но is the best choice:

• Мне трудно..., но я могу...

That is exactly the kind of contrast но is commonly used for.

Russian stress is important because it is not always predictable. In this sentence, the usual stresses are:

• мне
• тру́дно
• произноси́ть
• дли́нные
• слова́
• бы́стро
• но
• я
• могу́
• произнести́
• их
• пра́вильно
• е́сли
• не
• спешу́

A few especially useful ones to notice:

• слова́ has stress on the last syllable
• могу́ has stress on the last syllable
• спешу́ has stress on the last syllable
• пра́вильно has stress on the first syllable

For learners, it is best to memorize Russian words together with stress, especially verbs and common adverbs.