La revisión dura veinte minutos.

Because revisión is a feminine singular noun, so it takes the feminine singular definite article la.

• la revisión = the check-up / the inspection / the review
• If the noun were masculine, you would use el instead.

This is one of the first things Spanish learners need to notice: nouns usually come with an article more often than in English.

Revisión is a noun. Depending on context, it can mean things like:

• check-up
• inspection
• review
• revision

In this sentence, the exact English translation depends on context, but grammatically it is simply a feminine noun: la revisión.

A learner may also notice that revisión is related to English words like revision and review, which can help with remembering it.

Because durar means to last. When you want to say how long something continues, Spanish normally uses durar.

• La revisión dura veinte minutos. = The check-up lasts twenty minutes.

You would not normally use ser or estar for duration in this structure.

Compare:

• La película dura dos horas. = The film lasts two hours.
• La reunión dura media hora. = The meeting lasts half an hour.

So dura is the natural verb here.

In this sentence, dura is a verb: the third-person singular present form of durar.

That matters because dura can also be an adjective in other contexts:

• una mesa dura = a hard table
• la situación es dura = the situation is hard/tough

But here, because it follows the noun and introduces a length of time, it is clearly the verb:

• La revisión dura veinte minutos.

So here it means lasts, not hard or tough.

Because the subject is la revisión, which is third-person singular.

The present tense of durar starts like this:

• yo duro
• tú duras
• él / ella / usted dura
• nosotros duramos
• vosotros duráis
• ellos / ellas / ustedes duran

Since la revisión is like it, Spanish uses dura.

Because in Spanish, with durar, the duration usually comes directly after the verb.

• dura veinte minutos
• duró tres horas
• durará una semana

English often uses for in some structures, but Spanish does not need an equivalent here.

So:

• It lasts twenty minutes → dura veinte minutos
• not dura por veinte minutos in this neutral statement

Because veinte is a number, and in this structure it does not change for gender.

• veinte minutos
• veinte horas
• veinte páginas

Unlike some words in Spanish, veinte stays the same whether the noun is masculine or feminine.

Because the quantity is more than one: veinte.

In Spanish, just like in English, countable nouns usually become plural after numbers greater than one.

• un minuto
• dos minutos
• veinte minutos

So minutos must be plural here.

Yes. That would mean about twenty minutes or some twenty minutes, depending on tone.

• La revisión dura veinte minutos. = exactly or neutrally twenty minutes
• La revisión dura unos veinte minutos. = about twenty minutes

This is a very common way to make the duration approximate.

Yes, but the basic order here is the most neutral and common:

• La revisión dura veinte minutos.

You might hear different word order for emphasis, but it is less neutral:

• Veinte minutos dura la revisión.

That sounds more marked or literary. For most learners, the standard order is the one to use.

Yes. Since la revisión is a singular thing, you could replace it with ella in theory, though Spanish usually just keeps the noun or omits the subject if the context is clear.

Most natural options:

• Dura veinte minutos. = It lasts twenty minutes.
• La revisión dura veinte minutos.

Spanish often drops the subject because the verb ending already shows the person and number.

A few useful points:

• The written accent in revisión shows that the stress falls on the last syllable: re-vi-sión
• The final -ión is very common in Spanish nouns
• In Spain, s is clear, and v and b are pronounced very similarly

So a rough guide is: reh-bee-SYON or reh-vee-SYON, with the stress on the last part.

Not necessarily. The Spanish present tense can also express a general fact or a scheduled event.

So La revisión dura veinte minutos can mean:

• that this is generally how long such a check-up lasts
• that today’s check-up is scheduled to last twenty minutes

This is very normal in Spanish and English alike.