Por eso va aprendiendo a decir que no cuando el banco le ofrece otra tarjeta de crédito.

All three are grammatical, but they suggest slightly different things:

• aprende a decir que no
  = “he/she learns / is learning to say no” (basic present, neutral about how the process feels)

• está aprendiendo a decir que no
  = “he/she is learning to say no (right now / these days)” – focuses on an ongoing process in the present.

• va aprendiendo a decir que no
  literally “he/she goes learning to say no.”
  In practice: “he/she is gradually learning / is slowly getting better at saying no.”

ir + gerundio (like va aprendiendo) often implies gradual, step‑by‑step progress over time. That’s why it’s used here: it highlights that learning to say no is a progressive, not instant, change.

In Spanish, when aprender is followed by another verb, you normally use aprender a + infinitive:

• aprender a leer – to learn to read
• aprender a conducir – to learn to drive
• aprender a decir que no – to learn to say no

Leaving out a (aprender decir) sounds wrong to native speakers. The a is part of the structure aprender a + infinitive.

All of these can appear in Spanish:

• decir no
• decir "no"
• decir que no

In practice:

• decir "no" is very literal, like quoting the word “no.”
• decir no is also understandable, but sounds more bare and less idiomatic here.
• decir que no is the most natural and common way to say “to say no” in this kind of sentence.

Spanish often uses que to introduce what is being said, thought, or felt:

• decir que sí / que no – to say yes / no
• pensar que… – to think that…
• creer que… – to believe that…

So aprender a decir que no is the most natural choice.

• por eso means “for that reason / that’s why / so”.
  It refers back to something mentioned before and introduces the consequence.

• porque means “because” and introduces the cause.

Compare:

• No quiere más deudas. Por eso va aprendiendo a decir que no.
  = He doesn’t want more debts. For that reason / That’s why he is learning to say no.

• Va aprendiendo a decir que no porque no quiere más deudas.
  = He is learning to say no because he doesn’t want more debts.

• así que is close to “so / therefore,” often more colloquial:
  No quiere más deudas, así que va aprendiendo a decir que no.

In this sentence, por eso neatly links a previous cause (not shown in the snippet) with the result.

Spanish usually omits subject pronouns because the verb ending already shows the subject:

• va aprendiendo is 3rd person singular (él / ella / usted).

Which one it is (he, she, you-formal) depends on context. In isolation, it’s most naturally understood as he or she:

• (Él / Ella) va aprendiendo a decir que no…

The pronoun is only added for clarity, emphasis, or contrast:

• Él va aprendiendo, pero ella todavía no.
  He is starting to learn, but she still isn’t.

Because le is an indirect object pronoun (“to him / to her / to you-formal”), and lo is a direct object pronoun (“it / him”).

In el banco le ofrece otra tarjeta de crédito:

• el banco = the subject (the bank)
• ofrece = offers (the action)
• otra tarjeta de crédito = direct object (what is being offered)
• le = indirect object (to whom it is offered)

So the structure is:
[The bank] offers [another credit card] to [him / her].

That “to him / to her” is le, so le ofrece is correct.

Le means “to him / to her / to you-formal”. The exact person is understood from context.

You can clarify or emphasize with a él / a ella / a usted, often together with le:

• El banco le ofrece otra tarjeta de crédito a él.
• El banco le ofrece otra tarjeta de crédito a ella.

The pattern a + person + le is normal and not redundant; it’s used for emphasis or to avoid ambiguity.

With cuando, Spanish uses:

• Indicative (here: ofrece) for habitual, repeated, or factual actions.
• Subjunctive (ofrezca) for future or uncertain actions that haven’t happened yet.

In this sentence, it describes a repeated situation:

• Every time / whenever the bank offers another card, he/she is gradually learning to say no.

That’s habitual, so cuando el banco le ofrece otra tarjeta de crédito (indicative) is correct.

If you were talking about a future event that hasn’t happened yet, you’d use subjunctive:

• Va a decir que no cuando el banco le ofrezca otra tarjeta de crédito.
  He/She will say no when the bank offers another credit card. (future, not habitual)

In Spanish, otra already includes the idea of “one more / another”, so you don’t add una:

• otra tarjeta de crédito = another credit card
  NOT: una otra tarjeta de crédito (incorrect)

Compare:

• una tarjeta de crédito – a credit card
• otra tarjeta de crédito – another (one)

• otra tarjeta de crédito
  = another credit card / one more card (singular, one additional card).

• más tarjetas de crédito
  = more credit cards (plural, an unspecified number greater than the current one).

So if the bank is offering one additional card, otra tarjeta de crédito is the natural choice.

Adjectives in Spanish typically follow the noun, but several common adjectives usually come before it, including:

• otro/otra (other, another)
• este/ese/aquel (this/that)
• mi/tu/su (my/your/his/her/their)

So you say:

• otra tarjeta de crédito
  not tarjeta otra de crédito

Placing otra after tarjeta would sound ungrammatical here.

You can move some elements, but with limits:

1. The pronoun le normally stays before the conjugated verb:

   • El banco le ofrece otra tarjeta de crédito.
   • Le ofrece otra tarjeta de crédito el banco. (possible, but marked/emphatic)

2. You can’t say ofrece le:

   • ✗ El banco ofrece le otra tarjeta de crédito. (incorrect)

3. Dropping the subject is also possible if it’s already known:

   • Le ofrece otra tarjeta de crédito.
     (context must make it clear that el banco is the one offering)

So small changes for emphasis are allowed, but the safe, neutral word order is the original one.