El oficial llegó temprano.

El is the masculine singular definite article, meaning the.

You use el oficial when you are talking about a specific official/officer that is known from the context.

• El oficial llegó temprano. = a specific person arrived early.
• Oficial by itself would usually not work as a complete noun phrase here.

Also, oficial is masculine in this sentence, so the article is el, not la.

Llegó is the preterite form of llegar.

It is:

• 3rd person singular
• used for a completed past action

So it corresponds to:

• he arrived
• she arrived
• it arrived
• the official arrived

In this sentence, el oficial is the subject, so llegó means the official arrived.

The accent mark shows both stress and meaning.

• llegó = he/she/it arrived (preterite)
• llego = I arrive / I am arriving would actually be incorrect for standard spelling; the correct present form is llego, but without the accent it is pronounced differently and means I arrive

More clearly:

• llego = I arrive
• llegó = he/she arrived

The written accent helps distinguish these forms.

It also shows that the stress falls on the last syllable: lle-GÓ.

Spanish often omits subject pronouns because the verb ending already tells you who the subject is.

• llegó already tells you it is he/she/it or a singular noun subject.
• Since el oficial is already stated, adding él would usually be unnecessary.

So:

• El oficial llegó temprano. is the normal way to say it.

Spanish uses subject pronouns more often only for:

• emphasis
• contrast
• avoiding ambiguity

Here, temprano is functioning as an adverb, meaning early.

It describes when the official arrived.

• llegó temprano = arrived early

This is useful because temprano can also be an adjective in other contexts:

• una hora temprana = an early hour

But in your sentence, it modifies the verb llegó, so it is adverbial.

In Spanish, adverbs like temprano, tarde, bien, and mal often come after the verb.

So:

• llegó temprano is the natural word order.

This is similar to English in many cases:

• arrived early

Spanish word order is somewhat flexible, but this version is the most neutral and natural.

A common Spain pronunciation would be approximately:

el o-fi-THYAL ye-GO temprano

A few details:

• oficial: in much of Spain, the ci sounds like thy in thin
• llegó: in most of Spain, ll sounds like y
• gó: the stress is on the last syllable
• temprano: stress on pra

A rough IPA version for much of Spain is:

[el ofiˈθjal ʝeˈɣo temˈpɾano]

Yes. Oficial can have more than one meaning depending on context.

It can refer to:

• an official
• an officer
• sometimes a person with a rank or position in an institution

So the exact English word depends on the situation.

For example:

• in government or administration, it may be official
• in military or police contexts, it may be officer

That is why context matters.

Yes, you could, but it means something slightly different in tone or viewpoint.

• El oficial llegó temprano. = simple completed past; very common for narration
• El oficial ha llegado temprano. = present perfect; often connects the past event more directly to the present

In Spain, the present perfect is used quite a lot for recent past events, especially when the time period is still connected to the present.

For example:

• Hoy el oficial ha llegado temprano. = Today the official has arrived early
• Ayer el oficial llegó temprano. = Yesterday the official arrived early

So both are possible, but they are not always interchangeable.

Not in this sentence, because temprano is an adverb, not a destination.

But with llegar, you often use a before a place:

• Llegó a casa temprano. = He arrived home early
• Llegó al edificio temprano. = He arrived at the building early

So:

• llegó temprano = arrived early
• llegó a Madrid temprano = arrived in Madrid early

Yes, that word order is possible, but it sounds less neutral.

• El oficial llegó temprano. = standard, neutral order
• Llegó temprano el oficial. = more marked; it may sound literary, emphatic, or like you are introducing the subject afterward

Spanish allows more flexibility in word order than English, but the original sentence is the most straightforward version for everyday use.