Ontem eu usei outro cupom e paguei menos pelo arroz.

Ontem means yesterday, and it sets the time for the whole sentence.

In Portuguese, time expressions often go at the beginning very naturally:

• Ontem eu usei outro cupom...
• Eu usei outro cupom ontem...

Both are correct. Putting ontem first gives the sentence a nice natural flow and immediately tells the listener when the action happened.

Both usei and paguei are in the preterite tense, which is used for completed actions in the past.

• usei = I used
• paguei = I paid

This fits because the speaker is talking about specific finished actions that happened yesterday.

The infinitives are:

• usar = to use
• pagar = to pay

First-person singular in the preterite:

• eu usei
• eu paguei

Yes, it can be omitted.

Portuguese often leaves out subject pronouns when the verb ending already makes the subject clear. So both of these are natural:

• Ontem eu usei outro cupom e paguei menos pelo arroz.
• Ontem usei outro cupom e paguei menos pelo arroz.

Including eu can add clarity, emphasis, or simply reflect the speaker’s style. In Brazilian Portuguese, subject pronouns are used more often than in European Portuguese, so eu sounds completely normal here.

Outro means another or a different.

So outro cupom means another coupon / a different coupon.

Compare:

• outro cupom = another, different coupon
• mais um cupom = one more coupon

Sometimes these are close in meaning, but outro especially highlights that it was a different one.

In Portuguese, outro often works without um.

So:

• outro cupom = very natural
• um outro cupom = also possible, but usually more emphatic or stylistically marked

For most everyday situations, outro cupom is the most normal choice.

Cupom means coupon, and in Brazil it is commonly used for:

• discount coupons
• promo codes
• store/app discount offers

Depending on context, you may also hear:

• cupom de desconto = discount coupon / discount code

So in this sentence, outro cupom most likely means another discount coupon or promo code.

Paguei menos means I paid less, which is the most natural structure here.

In Portuguese:

• pagar menos = to pay less
• ser mais barato = to be cheaper

So these are different ideas:

• Paguei menos pelo arroz. = I paid less for the rice.
• O arroz estava mais barato. = The rice was cheaper.

Learners sometimes try to translate I paid cheaper, but Portuguese usually prefers pagar menos, not pagar mais barato.

Pelo is a contraction of:

• por + o = pelo

Here, por means for in the sense of payment:

• pagar por algo = to pay for something

Since arroz is masculine singular and uses the article o, the contraction happens:

• por o arroz → pelo arroz

So:

• paguei menos pelo arroz = I paid less for the rice

In Portuguese, nouns often appear with definite articles more often than in English.

So o arroz can mean:

• the rice
• rice, in a general/contextual sense

In this sentence, pelo arroz sounds natural because Portuguese commonly says pagar pelo arroz, pelo pão, pela carne, etc.

Even when English might simply say for rice, Portuguese often uses the article.

Because both verbs have the same subject: eu.

So:

• eu usei outro cupom
• (eu) paguei menos pelo arroz

Portuguese, like English, does not need to repeat the subject if it stays the same:

• Yesterday I used another coupon and paid less for the rice.

Repeating eu would be possible, but unnecessary here.

Yes. Ontem applies to both actions:

• used another coupon
• paid less for the rice

Since the two verbs are linked by e (and) and are in the same tense, the time expression naturally covers both unless context suggests otherwise.

This comes from the spelling rules of Portuguese.

The verb is pagar. In the preterite first person, the ending is -ei, so you might expect something like pagei, but that would change the sound of the g.

Portuguese keeps the hard g sound by writing:

• paguei

Compare:

• pagar
• eu paguei

This is similar to other verbs where spelling changes preserve pronunciation.

In Brazilian Portuguese, paguei is approximately pronounced like:

• pah-GAY

More precisely:

• pa = like pah
• guei = roughly like gay, but with Portuguese vowel quality

The u in guei is not strongly pronounced as a separate vowel here; it mainly helps keep the hard g sound.

Yes, but it is a slightly different structure.

• Paguei menos pelo arroz. = I paid less for the rice.
• Comprei o arroz por menos. = I bought the rice for less.

Both are understandable and natural, but paguei menos pelo arroz focuses more directly on the amount paid.

Yes, it sounds natural and everyday.

A Brazilian speaker could easily say:

• Ontem eu usei outro cupom e paguei menos pelo arroz.

Some small variations that are also natural:

• Ontem usei outro cupom e paguei menos pelo arroz.
• Ontem eu usei outro cupom e o arroz saiu mais barato.
• Ontem eu usei outro cupom e economizei no arroz.

But the original sentence is completely normal and correct.