Guardo las gafas de sol en el bolso antes de entrar en la galería.

Because Spanish often uses the present tense to describe a habit, a routine, or something that happens in a general situation.

So Guardo las gafas de sol en el bolso antes de entrar en la galería can mean:

• I put my sunglasses in my bag before going into the gallery
• I usually put my sunglasses in my bag before entering the gallery

It does not have to mean only “right now, at this exact moment.” In Spanish, the present tense is very commonly used for everyday actions and habits.

Here, guardar means to put away, to store, or to keep something somewhere safely.

So in this sentence, guardo las gafas de sol en el bolso means:

• I put the sunglasses in my bag
• I store the sunglasses in my bag

It is not the same as mirar (“to look at”) or llevar (“to carry/wear”).
A useful idea is that guardar often implies putting something in its proper place.

Spanish often uses the definite article (el, la, los, las) where English might use my, your, or no article at all.

So las gafas de sol literally means the sunglasses, but in context it often naturally means:

• my sunglasses
• the sunglasses

Spanish does this a lot with everyday objects when ownership is already obvious from the context.

Compare:

• Guardo las gafas = I put my/the glasses away
• Guardo mis gafas = I put my glasses away

Both are possible, but las gafas sounds very natural when it is already clear whose glasses they are.

In Spanish, gafas is normally used in the plural, just like glasses in English.

So:

• las gafas = glasses
• las gafas de sol = sunglasses

Even if it is one physical object, Spanish treats it as plural because it has two lenses/sides, just as English does with glasses.

You would not normally say la gafa to mean “a pair of glasses.”

De sol literally means of sun, but in natural English it means sun as a type or purpose.

So:

• gafas de sol = sunglasses
• literally: glasses for the sun

This is a very common Spanish structure:

• gafas de lectura = reading glasses
• crema de manos = hand cream
• bolsa de deporte = sports bag / gym bag

So de + noun often tells you what something is for or what type it is.

En el bolso means in the bag.

• en = in / into / inside, depending on context
• el bolso = the bag / handbag

With guardar, Spanish commonly uses en to show where something is being placed:

• Guardo el móvil en el bolsillo = I put my phone in my pocket
• Guardo las llaves en el cajón = I put the keys in the drawer

So en el bolso tells you the destination or location where the sunglasses end up.

In Spain, bolso usually means a handbag, purse, or sometimes a personal bag.
Bolsa more often means a bag like a shopping bag or plastic/paper bag.

So:

• bolso = handbag / purse / personal bag
• bolsa = bag, shopping bag, carrier bag

In this sentence, bolso suggests a personal bag, which fits naturally with putting sunglasses away before entering somewhere.

Because after antes when a verb follows, Spanish uses de + infinitive.

So the pattern is:

• antes de + infinitive

Examples:

• antes de salir = before leaving
• antes de comer = before eating
• antes de entrar = before entering

This is a fixed structure, so antes entrar would be incorrect.

Yes, both can exist, but in Spain, entrar en is very common and very standard.

So:

• entrar en la galería = to enter the gallery
• entrar a la galería = also possible, especially in some regions and more common in much of Latin America

For a learner focusing on Spanish from Spain, entrar en is a very good choice to learn and use.

Because en has a broad meaning in Spanish and is used in many situations where English may use different prepositions.

Here:

• en el bolso = in the bag
• entrar en la galería = to enter the gallery

So the same preposition appears twice, but it is doing slightly different jobs:

1. showing where something is placed
2. following the verb entrar

This is normal in Spanish. A single preposition often covers several meanings that English splits into different words.

Spanish often uses the definite article with places more than English does.

So la galería means:

• the gallery

If both speaker and listener know which gallery is meant, Spanish naturally includes the article.

This is very common with places:

• voy al banco = I’m going to the bank
• entro en la tienda = I go into the shop
• salgo de la oficina = I leave the office

English sometimes drops the article in similar contexts, but Spanish usually keeps it.

Yes. Without extra context, it can easily describe a habit or routine.

For example:

• Before entering the gallery, I put my sunglasses in my bag.
• I always put my sunglasses in my bag before entering the gallery.

If you wanted to make the habitual meaning clearer, you could add something like:

• Siempre guardo las gafas de sol en el bolso antes de entrar en la galería.

But even without siempre, the present tense already allows that interpretation.

Probably, but not absolutely from grammar alone.

Galería can mean different kinds of gallery, depending on context. However, because the sentence mentions putting sunglasses away before entering, many learners will naturally understand it as something like an art gallery or an indoor gallery space.

So the exact kind of gallery comes more from context and the meaning you were given than from the grammar itself.