Ayer adoptamos una tortuga y hoy mi hija no deja de mirarla.

Adoptamos is the nosotros form of adoptar. With regular -ar verbs, that form is spelled the same in the present and the preterite:

• adoptamos = we adopt
• adoptamos = we adopted

So the form alone is ambiguous. Here, ayer makes it clear that it means we adopted.

Because ayer refers to a finished past time: yesterday. In Spanish, that normally calls for the preterite:

• Ayer adoptamos una tortuga. = Yesterday we adopted a turtle.

This is especially important for Spain Spanish learners because Spain often uses the present perfect for recent past connected to the present, for example with hoy. But with ayer, the natural choice is still the preterite, not hemos adoptado.

Literally, it means she doesn’t stop looking at it/her.

Very naturally in English, you could translate it as:

• she can’t stop looking at it
• she keeps looking at it
• she won’t stop staring at it

So no dejar de + infinitive is a common way to express that someone continues doing something again and again.

It is part of the fixed structure dejar de + infinitive, which means to stop doing something or, in the negative, to not stop doing something.

Compare:

• Deja de hablar. = Stop talking.
• No deja de hablar. = He/She won’t stop talking.

Without de, dejar usually means something else, such as to leave or to let.

Because object pronouns in Spanish usually go:

• before a conjugated verb, or
• attached to an infinitive

Here, mirar is an infinitive, so the pronoun la is attached to it:

• mirarla = to look at it/her

In this kind of verbal structure, Spanish also often allows the pronoun before the first verb:

• No deja de mirarla
• No la deja de mirar

Both are possible, but attaching it to the infinitive is very natural here.

Because tortuga is a feminine noun in Spanish:

• una tortuga
• la tortuga

So the direct object pronoun that refers back to it is la.

Spanish pronouns often follow grammatical gender, not the English habit of using it for animals or objects. So even though English usually says it, Spanish says la here because tortuga is feminine.

Because mirar usually means to look at, while ver usually means to see.

• ver = to see, to perceive with your eyes
• mirar = to look at, to direct your eyes toward something

In this sentence, the daughter is actively looking at the turtle, so mirar is the right verb.

Because Spanish often leaves out subject pronouns when the verb already makes the subject clear.

• adoptamos already tells you the subject is we
• so nosotros is unnecessary unless you want emphasis or contrast

This is very normal in Spanish. English usually needs the subject pronoun, but Spanish often does not.

They help contrast the two actions clearly:

• Ayer: the adoption happened yesterday
• hoy: the daughter’s reaction is happening today

So the sentence is structured to show a neat timeline:

1. Yesterday we adopted a turtle.
2. Today my daughter keeps looking at it.

That contrast is one of the main points of the sentence.