Learn Hardcore Italian: Mia sorella guadagna poco, però promette a se stessa di non arrendersi. - My sister earns little, yet she promises herself not to give up.

In Italian, with singular close family members you normally drop the article: mia sorella, mio padre, mio fratello. You do use the article:

when the noun is modified: la mia sorella maggiore, la mia sorellina
with the possessive loro: la loro sorella
in the plural: le mie sorelle Outside these cases, avoid la mia sorella.

Why poco and not pochi or poca?

Here poco is an adverb meaning little, and adverbs don’t agree: guadagnare poco = to earn little. As an adjective, it does agree with the noun: pochi soldi, poca pazienza.

What’s the difference between poco and un po'?

poco = little, not much (often a negative/insufficient amount): guadagna poco.
un po' = a bit, some (softer/neutral): guadagna un po' suggests a small but acceptable amount. Note the apostrophe in po'.

Why use però instead of ma? Are they interchangeable?

Both mean but. ma is the basic conjunction. però is closer to however/but, slightly more conversational and flexible in placement. In most contexts you can swap them:

Guadagna poco, ma promette...
Guadagna poco, però promette...

Where can però go, and do I need a comma?

Common options:

Mid-clause after a comma: ..., però ...
At the start: Però, ... (colloquial) or sometimes Però ... without a comma in short sentences. Use a comma when you’re clearly separating two clauses.

Is the accent in però mandatory?

Yes. Write però with the accent on the final ò.

Why is it promette a se stessa and not si promette?

promettere a se stessa = to promise to herself (indirect object with a).
promettersi exists but usually means to expect/aim for: non mi prometto grandi risultati. So si promette di non arrendersi sounds odd/ambiguous. Use promette a se stessa di....

Should it be se stessa or sé stessa with an accent?

Traditional rule: the stressed reflexive pronoun takes an accent (sé) except when followed by stesso/medesimo, where the accent is commonly dropped. So a se stessa is standard; a sé stessa also appears and is accepted by many, but a se stessa is the safest choice.

Why a se stessa but di non arrendersi? Why those prepositions?

promettere qualcosa a qualcuno uses a for the indirect object: promettere a se stessa.
promettere di + infinitive introduces the promised action: promette di non arrendersi. Together: promette a se stessa di ....

Why is arrendersi reflexive, and how do I negate it correctly?

arrendersi is inherently reflexive: to surrender/give up. With the infinitive after di, the clitic attaches to the verb: arrender-si. Negation:

Infinitive: di non arrendersi (not di non si arrendere).
Finite verb: non si arrende.

Can I say promette che non si arrenderà instead?

Yes. Promettere che + clause is fine: ... promette che non si arrenderà. The future (si arrenderà) is natural there. The di + infinitive version is just more compact.

Where would mai go if I want to say never give up?

Use non ... mai:

Infinitive: promette di non arrendersi mai
Finite verb: non si arrenderà mai

What’s the nuance difference between arrendersi, rinunciare, and mollare?

arrendersi = to surrender/give up against difficulties/opposition.
rinunciare (a qualcosa) = to renounce/forgo something: rinunciare ai sogni.
mollare (colloquial) = to quit/let go: non mollare!

Why is it se stessa (feminine)? How would it change with other subjects?

It matches the subject’s gender/number:

me stesso / me stessa
te stesso / te stessa
se stesso / se stessa
noi stessi / noi stesse
voi stessi / voi stesse
se stessi / se stesse

How do I say this in the past?

arrendersi uses essere and agrees: si è arresa (she gave up), si sono arresi/arrese.
promettere uses avere and has irregular promesso: ha promesso a se stessa di non arrendersi.

Is a lei stessa acceptable instead of a se stessa?

Grammatically yes, a lei stessa is possible for emphasis or to avoid ambiguity, but when the recipient is the subject, Italians strongly prefer the reflexive form a se stessa.

Can I change the word order, e.g., Mia sorella però guadagna poco or Però, mia sorella guadagna poco?

Yes. Both are idiomatic:

Mia sorella, però, guadagna poco.
Però, mia sorella guadagna poco. These change the rhythm/focus but not the meaning. The original order is very natural.