Промокод дал хорошую скидку, и заказ стал дешевле.

Дал is the past tense of дать (to give). In this sentence, Промокод дал хорошую скидку literally means The promo code gave a good discount.

This is a very natural way in Russian to say that a promo code provided or resulted in a discount.

Also, дал is masculine singular because промокод is a masculine noun.

Because скидку is the direct object of дал, it has to be in the accusative case.

• nominative: хорошая скидка = a good discount
• accusative: хорошую скидку = a good discount as the object of the verb

Since скидка is a feminine noun, both the noun and adjective change:

• скидка → скидку
• хорошая → хорошую

So:

• Промокод дал хорошую скидку = The promo code gave a good discount

Because this sentence joins two separate clauses:

1. Промокод дал хорошую скидку
2. заказ стал дешевле

Each clause has its own subject and verb:

• промокод
  • дал
• заказ
  • стал

In Russian, when и connects two independent clauses like this, a comma is normally used.

So the comma is correct here.

The verb стать often means to become.

So:

• заказ = order
• стал = became
• дешевле = cheaper

Together:

• заказ стал дешевле = the order became cheaper

This is a very common Russian pattern:

• стать лучше = to become better
• стать проще = to become simpler
• стать дешевле = to become cheaper

Дешевле is the comparative form of дешёвый (cheap).

• дешёвый = cheap
• дешевле = cheaper

In this sentence, Russian uses the comparative directly after стал:

• заказ стал дешевле

English needs became cheaper, and Russian works in a very similar way.

You do not need a word for more here. Russian often forms comparatives as a single word.

These forms mean different things.

• стал дешёвым = became cheap
• стал дешевле = became cheaper

In the sentence, the idea is that the order became cheaper than before, not necessarily absolutely cheap. So the comparative дешевле is the natural choice.

In Russian past tense, the verb agrees with the subject in gender and number.

• промокод is masculine singular, so: дал
• заказ is masculine singular, so: стал

Compare:

• скидка дала ... because скидка is feminine
• письмо дало ... because письмо is neuter
• заказы стали ... because заказы is plural

So the verb endings help show what kind of subject is doing the action.

Because промокод is the subject of the first clause.

In Russian, the subject is usually in the nominative case:

• Промокод дал хорошую скидку.

Here, промокод is the thing that gave the discount, so nominative is correct.

Yes. Russian word order is more flexible than English, although the original sentence is neutral and natural.

For example, you could also say:

• Хорошую скидку дал промокод, и заказ стал дешевле.
• Заказ стал дешевле, потому что промокод дал хорошую скидку.

But the original:

• Промокод дал хорошую скидку, и заказ стал дешевле.

is the most straightforward and neutral version.

Changing word order often changes emphasis, not the basic meaning.

Because this is natural Russian phrasing.

Russian often expresses this idea as:

• промокод дал скидку = the promo code gave a discount
• заказ стал дешевле = the order became cheaper

English might say:

• The promo code gave a good discount
• The promo code made the order cheaper
• The order became cheaper because of the promo code

Russian prefers these simple result-focused verbs. So even if the wording feels slightly different from English, it is idiomatic.

Yes. Both verbs are perfective here:

• дать → дал
• стать → стал

Perfective verbs present the actions as completed results:

• the promo code gave the discount
• the order became cheaper

That fits the sentence well, because it describes a finished outcome.

If you used imperfective verbs like давал or становился, the meaning would change and would sound less natural here. Those forms would suggest an ongoing, repeated, or process-like action rather than a simple completed result.