Аккуратность в тетради не только радует учителя, но и помогает мне повторять правила.

В тетради means in the notebook.

The preposition в can mean either:

• into
  • accusative, when there is movement
• in
  • prepositional, when talking about location

Here there is no movement, just location, so Russian uses the prepositional case:

• тетрадь = notebook
• в тетради = in the notebook

Because тетрадь is in the prepositional singular after в.

Its basic form is:

• тетрадь = notebook

After в in the sense of in, it changes to:

• в тетради

This is normal for many feminine nouns ending in -ь.

This is a fixed Russian pattern meaning not only ..., but also ....

So:

• не только радует учителя
• но и помогает мне повторять правила

together mean:

• not only pleases the teacher, but also helps me review the rules

This structure is very common in Russian and works much like it does in English.

Because учителя is the direct object of the verb радует: the neatness pleases the teacher.

The verb радовать takes an object in the accusative case.

With animate masculine nouns, the accusative singular looks like the genitive singular:

• учитель = teacher
• учителя = teacher (as object)

So радует учителя literally means pleases the teacher.

Because the verb помогать usually takes the person being helped in the dative case.

So:

• я = I
• мне = to me

That is why Russian says:

• помогает мне = helps me

Literally, it is closer to helps to me, even though in natural English we just say helps me.

Повторять is the imperfective form, and here it fits because the meaning is general or repeated: neat work helps the speaker review or go over rules regularly.

• повторять = to review / repeat / go over, as a process
• повторить = to review once, to complete the review

So in this sentence, повторять sounds more natural because it describes an ongoing benefit, not one completed action.

Because it is the thing doing the action in the sentence.

• Аккуратность ... радует
• Аккуратность ... помогает

So Аккуратность is the subject, and the verbs are in the 3rd person singular to match it:

• радует
• помогает

Even though English might sometimes prefer a structure like Being neat in your notebook..., Russian commonly uses an abstract noun like Аккуратность.

Yes, Russian word order is flexible, but the given version is natural and clear.

The original order puts the focus first on Аккуратность в тетради as the topic, then gives two results:

1. it pleases the teacher
2. it helps me review the rules

You could change the order in some contexts for emphasis, but this version is neutral and idiomatic.

Literally it means in the notebook, but in context it often means in one’s notebook or in the notebook/workbook being used.

Russian often leaves out possessive words like my when the meaning is clear from context. So depending on the situation, в тетради may naturally be understood as in my notebook or in the student’s notebook.

Russian has no articles. There is no direct equivalent of a or the.

So Russian simply says:

• учителя
• тетради
• правила

and the listener understands from context whether English would use a, the, or no article at all.

Правила means rules. In a school context, it often refers to grammar rules, spelling rules, or other study rules that the speaker is reviewing.

So помогает мне повторять правила means that neat notes make it easier for the speaker to go back and review the rules they have learned.