El pájaro de mi tía canta por la mañana, pero la tortuga siempre está en silencio.

Because Spanish nouns have grammatical gender, and the article has to match the noun:

• el = masculine singular
• la = feminine singular

So:

• el pájaro = the bird
• la tortuga = the turtle

The gender is a property of the noun itself, not necessarily of the animal’s real-life sex.

De mi tía means of my aunt or, more naturally in English, my aunt’s.

Spanish often shows possession with:

noun + de + owner

So:

• el pájaro de mi tía = my aunt’s bird

This is a very common structure in Spanish.

Because mi without an accent is the possessive adjective my.

• mi tía = my aunt

mí with an accent means me after a preposition:

• para mí = for me
• de mí = of me (rare in normal speech)

So here it must be mi tía, not mí tía.

In Spanish, you normally do not use an article before a singular possessive like mi, tu, su, etc.

So Spanish says:

• mi tía = my aunt

not

• la mi tía

That older-style form exists in some regional or literary uses, but it is not standard modern Spanish.

Canta is the third-person singular form of the verb cantar (to sing) in the present tense.

So:

• el pájaro canta = the bird sings

Because the subject is el pájaro (the bird), the verb has to match that singular third-person subject.

In many contexts, Spanish simple present can translate as either:

• sings
• is singing

depending on context.

Here, because of por la mañana (in the morning), it sounds like a habitual action, so sings is the most natural translation:

• The bird sings in the morning

If you wanted to emphasize that it is happening right now, Spanish would more likely use:

• está cantando = is singing

Por la mañana is the standard Spanish expression for in the morning.

Similar expressions are:

• por la tarde = in the afternoon / evening
• por la noche = at night / in the evening

You should usually learn por la mañana as a fixed time expression rather than translating word by word.

It can mean both, depending on context.

• mañana = tomorrow
• la mañana = the morning

In this sentence, por la mañana clearly means in the morning.

So the article la helps show that this is morning, not tomorrow.

Because estar is used for states or conditions, and en silencio describes the turtle’s state.

• está en silencio = is silent / is in silence

Using ser here would sound wrong.
A simple way to think about it is:

• ser = what something is
• estar = how something is / the state it is in

Silence here is being treated as a state, so estar is the correct verb.

Literally, it means in silence, but natural English usually says:

• silent
• quiet
• in silence

So:

• la tortuga siempre está en silencio = the turtle is always silent / always quiet

Spanish often uses estar en + noun to describe a state.

In Spanish, adverbs like siempre (always) often go before the conjugated verb:

• siempre está

This is a very normal word order.

You may also hear está siempre, but siempre está is more neutral and common in this kind of sentence.

Pero means but.

It connects two contrasting ideas:

• The bird sings in the morning
• but the turtle is always silent

So it introduces a contrast between the bird and the turtle.

Because pero joins two complete ideas, and Spanish often uses a comma before it in this situation, much like English does before but.

So the comma helps separate the two clauses clearly:

• El pájaro de mi tía canta por la mañana
• pero la tortuga siempre está en silencio

The accent marks show stress, and sometimes they also help distinguish words.

• pájaro: the stress is on pá
• tía: the stress is on tí
• está: the stress is on the last syllable

In tía, the accent also helps show that the i and a are pronounced separately: TEE-ah, not as one blended syllable.

Accent marks in Spanish are important and should not be ignored in writing.

The key letter is ñ, which is pronounced like ny in canyon.

So mañana is approximately:

• ma-NYA-na

Not ma-na-na.

This ñ sound is very common in Spanish and is different from a plain n.

No. Spanish usually does not need subject pronouns when the subject is already clear.

Here the subjects are explicitly named:

• El pájaro ... canta
• la tortuga ... está

So adding él or ella would be unnecessary.

Spanish often leaves pronouns out unless they are needed for emphasis or contrast.

Yes, Spanish word order is somewhat flexible, though the original sentence is the most neutral and natural.

For example, you could also say:

• Por la mañana, el pájaro de mi tía canta...

This puts extra focus on in the morning.

But the original version is a very standard, natural way to say it.