Șoferul remediază deficiența majoră.

Because Romanian usually puts the definite article at the end of the noun, not before it as English does.

• șofer = driver
• șoferul = the driver

For a masculine singular noun like șofer, the definite article is often -ul.

So Șoferul means the driver.

For the same reason: Romanian attaches the definite article to the noun itself.

• deficiență = a deficiency / a defect / a fault
• deficiența = the deficiency / the defect

Here deficiență is feminine singular, and its definite form is deficiența.

So deficiența majoră means the major deficiency.

Remediază is the 3rd person singular present tense of a remedia.

That means it matches a singular subject like șoferul:

• a remedia = to remedy / to correct / to fix
• el/ea remediază = he/she remedies / fixes

So in this sentence, Șoferul remediază... means The driver remedies/fixes...

The base verb is a remedia, and in the present tense many Romanian verbs ending in -ia form el/ea with -iază.

So:

• a studia → studiază
• a copia → copiază
• a remedia → remediază

This is a normal pattern, even if it may look a little surprising at first.

In Romanian, adjectives usually come after the noun.

So:

• deficiență majoră = major deficiency
• literally: deficiency major

This is the normal word order in Romanian.
You can put an adjective before the noun in some contexts, but that often adds emphasis, style, or a slightly different tone.

Because the adjective has to agree with deficiența, which is:

• feminine
• singular

So the adjective also takes the feminine singular form:

• masculine singular: major
• feminine singular: majoră
• masculine plural: majori
• feminine plural: majore

Since deficiența is feminine singular, the correct form is majoră.

Because in Romanian, when the adjective comes after the noun, it usually does not take its own definite article.

So:

• deficiența majoră = the major deficiency

The noun is definite, and that is enough.
Romanian does not normally say something equivalent to the deficiency the major.

A different structure is possible when the adjective comes before the noun, but that is not what is happening here.

Because pe is often used to mark a direct object that is a person or specific animate being, not an inanimate thing like deficiența.

Compare:

• Văd șoferul. = I see the driver.
  Here pe șoferul is also very common because it is a person.
• Remediez deficiența. = I remedy the deficiency.
  No pe, because deficiența is not animate.

So in your sentence, pe is not needed.

The most important special letters here are:

• ș = sh as in ship
• ț = ts as in cats
• ă = a short uh sound, like a schwa

So:

• Șoferul begins with sh
• deficiența ends with -tsa
• majoră ends with -ruh / schwa-like ă
• remediază also ends with ă, so the last syllable sounds roughly like zuh

A rough English-friendly guide would be something like:

sho-fe-rul re-me-di-a-zuh de-fi-tsyen-tsa ma-jo-ruh

That is only approximate, but it helps with the main sounds.

Here it is mostly clear from meaning and word order.

• Șoferul is the one doing the action, so it is the subject
• deficiența majoră is the thing being fixed, so it is the direct object

Romanian often uses normal subject–verb–object order, just like English:

• Șoferul = subject
• remediază = verb
• deficiența majoră = object

Also, in this sentence, the noun forms do not give a special visible case ending that clearly separates subject from object, so word order and meaning do a lot of the work.

Yes, Romanian word order is more flexible than English, but Șoferul remediază deficiența majoră is the most neutral and straightforward version.

Other orders are possible for emphasis, for example:

• Deficiența majoră o remediază șoferul.
  This emphasizes the major deficiency
• Remediază șoferul deficiența majoră?
  This can sound like a question or a marked structure depending on intonation and context

So the original sentence is the best default pattern for a learner to remember.

They are close, but not always identical.

• a remedia = to remedy / correct / fix
• a repara = to repair

A remedia can sound a bit more formal or technical, and it often focuses on correcting a problem or deficiency rather than physically repairing an object.

So in this sentence, remediază deficiența majoră sounds natural if the idea is correcting a serious fault/deficiency.