El criterio de evaluación usa la escala de puntuación.

Because criterio is a masculine noun in Spanish, so it takes el.

A useful point for English speakers: nouns ending in -o are often masculine, and nouns ending in -a are often feminine, although there are exceptions.

• el criterio = the criterion
• el libro = the book
• la mesa = the table

So here, el agrees with criterio.

Criterio means criterion or sometimes standard, depending on context.

In this sentence, el criterio de evaluación is best understood as:

• the evaluation criterion
• or the assessment criterion

English often uses criterion in formal or academic contexts, and Spanish criterio works in a very similar way.

Here, de links two nouns and works like of in English.

So:

• criterio de evaluación = criterion of evaluation
• more natural English: evaluation criterion / assessment criterion

This is very common in Spanish. Instead of putting one noun directly before another, Spanish often uses de:

• escala de puntuación = scoring scale
• centro de salud = health centre
• libro de texto = textbook

So de is not always translated literally; often it just connects ideas in a way English expresses with a compound noun.

Because evaluación is a noun, meaning evaluation or assessment.

The phrase criterio de evaluación is a noun phrase, not a clause. It describes a type of criterion:

• criterio de evaluación = evaluation criterion
• literally: criterion of evaluation

If you used evaluar, that would be the infinitive verb to evaluate, and the structure would be different, for example:

• criterio para evaluar = criterion for evaluating

Both can exist, but they are not the same structure.

Usa is the third person singular present tense of usar.

So it means:

• he uses
• she uses
• it uses
• you use (formal singular, usted)

In this sentence, the subject is el criterio de evaluación, which is singular, so the verb must also be singular:

• El criterio ... usa ...

This is why it is usa, not usan.

The subject is El criterio de evaluación.

A good way to find the subject is to ask: What uses the scoring scale?

Answer: The evaluation criterion.

So the structure is:

• El criterio de evaluación = subject
• usa = verb
• la escala de puntuación = direct object

That means the sentence pattern is basically:

[subject] + [verb] + [object]

Because escala is a feminine singular noun, so it takes la.

• la escala = the scale

Spanish often uses definite articles more regularly than English does. In English, depending on context, you might say either:

• uses the scoring scale
• or sometimes just uses a scoring scale

But in Spanish, if a specific scale is meant, la is normal and expected.

Puntuación usually means score, scoring, or marking, depending on context.

In escala de puntuación, it refers to a scale used for assigning scores or marks.

So possible English equivalents are:

• scoring scale
• score scale
• marking scale

In educational contexts, scoring scale is often the most natural.

Be careful: puntuación can also mean punctuation in some contexts? Actually, no—that is puntuación only in some broad senses related to marking, but punctuation in the language sense is usually signos de puntuación or just puntuación depending on context. So context matters.

Because the stress falls on the final syllable: pun-tua-CIÓN.

Words ending in -n, -s, or a vowel normally have stress on the second-to-last syllable unless there is a written accent. Since this word is stressed on the last syllable, it needs the accent mark:

• puntuación

The accent helps show the correct pronunciation and stress.

A rough pronunciation guide is:

el kri-TE-rio de e-va-lua-THYON OO-sa la es-KA-la de pun-tua-THYON

In much of Spain, c before e or i is pronounced like the th in think:

• criterio → kri-TE-rio
• evaluación → ends with -thyon
• puntuación → ends with -thyon

But in parts of Spain and throughout Latin America, you may hear an s sound instead:

• evaluasión
• puntuasión

Both are valid depending on region.

Usa is perfectly correct, but depending on context, other verbs might also be possible.

For example:

• usa = uses
• emplea = employs / uses
• se basa en = is based on
• aplica = applies

The exact choice depends on meaning:

• El criterio de evaluación usa la escala de puntuación.
  The criterion uses the scoring scale.

• El criterio de evaluación se basa en la escala de puntuación.
  The criterion is based on the scoring scale.

So usa is straightforward and grammatical, but not the only possible verb in a similar context.

Yes, but the original order is the most neutral and standard:

• El criterio de evaluación usa la escala de puntuación.

Spanish word order is fairly flexible, but changes can affect emphasis. For example:

• La escala de puntuación la usa el criterio de evaluación.
  This is more marked and sounds like you are emphasizing the scoring scale.

For learners, it is best to stick with the basic order:

subject + verb + object

Yes, especially in formal, educational, or administrative language. It sounds quite natural in contexts like:

• rubrics
• school documents
• assessment guides
• grading criteria

That said, in everyday conversation, someone might choose wording that sounds a bit more explicit, such as:

• El criterio de evaluación se basa en esta escala de puntuación.
• Para evaluar, se usa esta escala de puntuación.

So the sentence is natural, but it sounds more like formal written Spanish than casual speech.