Learn Hardcore Spanish (Spain): De pequeña era muy sincera con mi familia. - As a little girl, I was very honest with my family.

So de pequeña could be understood more literally as “in (the time of being) little”, but it’s just the natural Spanish way to say “as a child / when I was young” when talking about yourself.

Why is pequeña feminine?

Because it agrees with the implied subject yo, and the speaker is understood to be female.

If the speaker is female → de pequeña
If the speaker is male → de pequeño

In Spanish, adjectives must agree in gender and number with the noun or pronoun they describe. Here, pequeña describes yo (a woman), so it’s feminine singular.

Could I say de pequeño if I’m a man?

Yes.

A woman would say: De pequeña era muy sincera con mi familia.
A man would say: De pequeño era muy sincero con mi familia.

You change both pequeña → pequeño and sincera → sincero to match the masculine subject.

Can I say cuando era pequeña instead of de pequeña? Is there a difference?

Yes, you can say Cuando era pequeña, era muy sincera con mi familia. It’s correct and clear.

Differences in nuance:

De pequeña is more idiomatic, shorter, and very common in everyday speech.
Cuando era pequeña is slightly more explicit (“when I was little”), a bit more neutral and descriptive.

In meaning, they’re essentially the same here. Both are fine.

Why is era used instead of fui?

Era is the imperfect form of ser, used for:

describing ongoing or repeated states in the past
describing characteristics in the past (what someone was like over a period of time)

Here, being muy sincera is a general characteristic of the speaker as a child, not a one-time event.

Era muy sincera = “I used to be / I was (as a general trait) very sincere.”

Fui (preterite) would suggest a completed event or a specific period viewed as a whole, which doesn’t fit as naturally with personality traits.

Why isn’t yo written? Could I say Yo, de pequeña, era muy sincera con mi familia?

Spanish often omits subject pronouns (like yo, tú, él) because the verb ending already shows who the subject is.

Era already indicates yo (I) from context, so yo is not necessary.

You can say:

Yo, de pequeña, era muy sincera con mi familia.

This adds a bit of emphasis on yo (“Me, when I was little, I was very sincere…”), but in normal conversation the version without yo is more natural and less heavy.

Why is it sincera and not sincero or honesta?

Sincera agrees with the subject, which is a woman → feminine.
Sincero would be the masculine form.
Honesta is another adjective, but it doesn’t always mean exactly the same.

Nuances:

sincera = straightforward, frank, telling the truth, not hiding things
honesta can mean honest, but in some contexts (especially traditionally) it can also carry connotations of “decent / morally proper,” and in everyday speech it’s less frequent than sincera to mean “always told the truth” or “very frank.”

So muy sincera is the most natural choice for describing a person who spoke very truthfully with her family.

Why is it con mi familia and not a mi familia?

Because in Spanish, with adjectives like sincero/sincera, you normally say you are sincere with someone:

ser sincero con alguien = to be sincere with someone

So:

Era muy sincera con mi familia. = I was very sincere with my family.

Using a would sound odd here. A is more common with verbs of movement or direction (escribir a, decir a, llamar a), not with ser sincero.

Why is it mi familia and not mis familia?

Because familia is singular in Spanish.

mi is used before singular nouns: mi familia, mi casa, mi hermano
mis is used before plural nouns: mis familias, mis casas, mis hermanos

Even though “family” includes several people, the word familia itself is grammatically singular, so you must say mi familia.

Could I change the word order to Era muy sincera con mi familia de pequeña? Is that still correct?

Yes, that’s also correct:

De pequeña era muy sincera con mi familia.
Era muy sincera con mi familia de pequeña.

Both are grammatical and natural.

Differences:

De pequeña at the beginning gives more emphasis to the time frame: “As a child, I was very sincere…”
At the end (…con mi familia de pequeña) it still means the same, but it’s slightly more neutral in rhythm. Many speakers use both orders interchangeably.

Is de pequeña used in the same way in Latin America as in Spain?

Yes, de pequeño / de pequeña is understood and widely used throughout the Spanish-speaking world to mean “when I was a child / as a kid.”

There might be regional preferences (some people might say cuando era niña, cuando era chico/a, etc.), but:

De pequeña (for women)
De pequeño (for men)

are common and natural in both Spain and Latin America.