Pasagerul cumpără obiectele de primă necesitate.

In Romanian, the definite article is usually attached to the end of the noun.

• pasager = a passenger / passenger
• pasagerul = the passenger

This is one of the first big differences from English. Instead of putting a separate word like the before the noun, Romanian often adds it as an ending.

For the same reason: obiectele is the definite plural form.

• obiecte = objects / some objects
• obiectele = the objects

So obiectele de primă necesitate means the essential items or the necessities, not just some essential items.

Cumpără is the 3rd person singular present tense of a cumpăra = to buy.

So it can mean:

• he buys
• she buys
• it buys

In this sentence, because the subject is pasagerul, it means the passenger buys.

A few present-tense forms of a cumpăra are:

• eu cumpăr = I buy
• tu cumperi = you buy
• el/ea cumpără = he/she buys
• noi cumpărăm = we buy
• voi cumpărați = you all buy
• ei/ele cumpără = they buy

It is a fixed expression meaning essential, basic, or necessary for everyday life.

So:

• obiecte de primă necesitate = essential items
• produse de primă necesitate = basic necessities / essential goods

Literally, it is something like of first necessity, but in natural English you would usually say essential items or basic necessities.

Because primă agrees with necesitate, which is a feminine singular noun.

In de primă necesitate, the structure is built around necesitate:

• necesitate = necessity
• primă necesitate = first necessity / essential need

Since necesitate is feminine singular, the adjective also appears in the feminine singular form: primă.

So the phrase is not describing obiectele directly. It is part of the expression de primă necesitate.

Romanian usually expresses the by adding it to the end of the noun, not by using a separate word.

In this sentence:

• pasagerul = the passenger
• obiectele = the objects / the items

So Romanian does have definiteness here, just in a different form from English.

Because obiectele is the direct object of the verb cumpără.

In Romanian, direct objects usually do not need a preposition:

• Cumpără obiectele. = He/She buys the objects.

Romanian sometimes uses pe before direct objects, but mainly with specific people or animate beings:

• Văd pasagerul. = I see the passenger.
• Îl văd pe pasager. = I see the passenger.
  This is common because the object is a person.

But with things like obiectele, pe is normally not used.

The normal, neutral order here is:

Pasagerul + cumpără + obiectele de primă necesitate
subject + verb + object

This is the most straightforward word order, and it matches English fairly well.

Romanian word order is somewhat flexible, though, especially for emphasis. For example, a different order could be used in context, but this sentence is the most neutral and standard version.

The Romanian ă is a short central vowel, similar to the a sound in English sofa for many speakers.

So:

• cumpără is roughly koom-puh-rə
• primă is roughly pree-mə

It is not a strong a like in father. It is a weaker, more relaxed vowel.

Yes. That is often the most natural English rendering.

A very literal version is:

• The passenger buys the objects of first necessity.

But natural English would usually say:

• The passenger buys essential items.
• The passenger buys basic necessities.

So even though the Romanian uses obiectele, the best English translation may be smoother than a word-for-word version.