Guardamos las maletas viejas en el desván.

Because Spanish often drops subject pronouns when the verb already shows who is doing the action.

• guardamos = we store / we keep / we put away
• So nosotros is not necessary.

You could say Nosotros guardamos las maletas viejas en el desván, but it sounds less neutral unless you want emphasis, contrast, or clarity.

Guardamos is the 1st person plural form of guardar.

Here it can be:

• present indicative: we store / we keep / we put away
• preterite: we stored / we put away

This form is one of those Spanish verb forms that is spelled the same in the present and the preterite for -ar verbs.

So the meaning depends on context.

Guardar is a very common verb with meanings such as:

• to keep
• to store
• to put away
• to save

In this sentence, it usually means something like to store or to put away.

It often suggests placing something somewhere for safekeeping or for later use.

Spanish uses the definite article more often than English.

So las maletas means the suitcases, and in context it can also sound natural where English might simply say old suitcases.

Using las suggests the suitcases are:

• specific
• known
• already identifiable in the situation

If you said Guardamos maletas viejas en el desván, that would sound more like We store old suitcases in the attic in a general sense.

In Spanish, most descriptive adjectives normally come after the noun.

So:

• maletas viejas = old suitcases

Putting the adjective before the noun is possible in some cases, but it usually changes the tone or nuance. For example, viejas maletas can sound more literary, emotional, or stylistically marked.

The most neutral order here is las maletas viejas.

Because of agreement.

• maletas is feminine plural
• viejas is also feminine plural
• desván is masculine singular

So viejas must go with maletas, not with desván.

This is one of the useful things about Spanish adjective agreement: it often makes relationships very clear.

Because adjectives in Spanish must agree with the noun in:

• gender
• number

Here:

• maleta is feminine
• maletas is plural

So the adjective must also be feminine plural:

• vieja → feminine singular
• viejas → feminine plural

That is why the sentence has las maletas viejas.

Because en means in / inside / on, and desván is a masculine singular noun, so it takes el:

• en + el desván = in the attic

Unlike a + el = al and de + el = del, en + el does not contract.

So en el desván is correct, not a shortened form.

Desván means attic or loft.

It has a written accent because of Spanish stress rules. Without getting too technical:

• words ending in n, s, or a vowel are normally stressed on the second-to-last syllable
• but desván is stressed on the last syllable
• so it needs the accent mark: desván

This tells you the pronunciation stress is on -ván.

Yes, Spanish word order is flexible, though the original is the most neutral.

Neutral order:

• Guardamos las maletas viejas en el desván.

Possible alternatives:

• En el desván guardamos las maletas viejas.
• Las maletas viejas las guardamos en el desván.

These alternatives usually add:

• emphasis
• contrast
• topic focus

But for a basic statement, the original order is the most natural.

Yes, viejo/vieja can have different shades of meaning depending on context, such as:

• old in age
• worn-out
• longstanding

With maletas, viejas most naturally means:

• old
• possibly old and worn

It does not mean former here. For objects, viejo/a is usually straightforward.

It can be understood either way depending on context, especially because guardamos can refer to both:

• a general/habitual situation: we keep/store the old suitcases in the attic
• a completed past action if it is preterite: we put away/stored the old suitcases in the attic

So the exact English translation depends on the wider context, not just the sentence by itself.