Reducimos la cantidad.

It is present indicative: we reduce.

With reducir, the nosotros present form is reducimos.

A very useful point: unlike many other verbs, reducimos is not the preterite form here. The preterite is redujimos (we reduced).

• reducimos = we reduce / we are reducing
• redujimos = we reduced

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

Here, -imos shows we in this verb form, so Reducimos la cantidad already means We reduce the amount.

You could say Nosotros reducimos la cantidad, but that usually adds emphasis, contrast, or clarity, for example:

• Nosotros reducimos la cantidad, no ellos.
  We reduced the amount, not them.

Because cantidad is a feminine singular noun, and here it is being treated as a specific amount: the amount.

• la cantidad = the amount / the quantity

Spanish often uses the definite article in places where English also uses the, so this is very natural.

Also, cantidad is feminine, so it takes la, not el.

Cantidad usually means amount or quantity.

In many everyday contexts, amount sounds more natural in English:

• Reducimos la cantidad de azúcar. = We reduced the amount of sugar.
• Reducimos la cantidad de agua. = We reduced the amount of water.

It can sometimes also mean quantity, especially in more formal, technical, or mathematical contexts.

It is mostly regular in the present tense, but it has an irregular yo form.

Present tense:

• yo reduzco
• tú reduces
• él/ella/usted reduce
• nosotros reducimos
• vosotros reducís
• ellos/ellas/ustedes reducen

So in this sentence, reducimos is a normal present-tense nosotros form.

A common thing to remember is that verbs like reducir often change to -zco in the yo form:

• reducir → reduzco
• conducir → conduzco

In standard Peninsular Spanish, the c before i is pronounced like the th in think.

So reducimos is approximately: reh-doo-THEE-mos

Meanwhile, in cantidad, the first c is before a, so it is pronounced like a normal k sound: kahn-tee-DAD

So:

• reducimos → c before i = th sound in much of Spain
• cantidad → c before a = k sound

Yes. The Spanish present tense often covers both:

• we reduce
• we are reducing

So depending on context, Reducimos la cantidad could refer to:

• a general action or habit
• something happening now

If you want to make the ongoing action especially clear, Spanish can also use: Estamos reduciendo la cantidad = We are reducing the amount

Yes. In this sentence, la cantidad is the direct object: it is the thing being reduced.

Structure:

• Reducimos = verb
• la cantidad = direct object

So the sentence pattern is basically: [We] reduce [the amount]

Yes, but Reducimos la cantidad is the most neutral and natural basic order.

Spanish usually prefers:

• Verb + object here, since the subject is omitted

You might see other orders for emphasis, for example:

• La cantidad la reducimos nosotros.

That sounds more emphatic, something like: It’s the amount that we reduce / We are the ones who reduce the amount

But for a simple statement, Reducimos la cantidad is the normal choice.

Yes, it could, depending on context.

Both reducir and disminuir can mean to reduce / to decrease, but they are not always used in exactly the same way.

• reducir la cantidad = to reduce the amount
• disminuir la cantidad = to decrease the amount

Reducir often sounds a bit more like an intentional act of cutting something down.
Disminuir can sound a bit more like something becomes less.

In this sentence, reducimos la cantidad is very natural and common.

In Spain, the informal plural you all form is vosotros, and the present-tense form is:

• vosotros reducís

So the full present-tense set used in Spain is:

• yo reduzco
• tú reduces
• él/ella/usted reduce
• nosotros reducimos
• vosotros reducís
• ellos/ellas/ustedes reducen

This is useful because learners of Spanish from Spain will commonly hear and use vosotros forms.