Learn Hardcore Spanish (Spain): Mi amiga deja el carrito junto a la entrada del supermercado. - My friend leaves the shopping cart next to the entrance of the supermarket.

A current action: “She is leaving the cart…”
A habitual action: “She leaves the cart…” You can use the progressive (está dejando) to stress the ongoingness, but it’s not required.

Does dejar mean “to leave” or “to let/allow”? How do I tell?

Both, depending on the pattern:

dejar + thing = to leave/put something somewhere. Example: Deja el carrito aquí.
dejar + a + person + infinitive or dejar que + subjunctive = to let/allow. Example: Me deja salir / Deja que salga.
dejar de + infinitive = to stop doing. Example: Deja de hablar.

Why el carrito and not un carrito or su carrito?

El carrito: a specific/known cart (often the one she’s been using).
Un carrito: introduces a cart not assumed to be known.
Su carrito: emphasizes it’s hers; use if you need to clarify possession. All are possible; choose by context.

What exactly is carrito in Spain? Are there other words?

In Spain, a supermarket cart is commonly carrito (de la compra) or carro (de la compra). All are natural:

carrito, carro, carrito de la compra, carro de la compra Note: coche = car (vehicle), not a shopping cart. Carrito de bebé/cochecito = stroller.

What does the -ito ending add here? Is the cart small?

-ito is a diminutive. It can mean “small,” but often softens/normalizes the noun. Carrito is the everyday term; it doesn’t imply a mini cart unless context says so.

How do you pronounce the Spanish j in deja and junto?

In Spain, j sounds like a harsh “h,” similar to the sound in Scottish “loch.”

deja ≈ “DE-ha”
junto ≈ “HUN-to” (with a throaty initial sound)

What does junto a mean exactly? How is it different from al lado de, cerca de, or en?

junto a = right next to, touching or very close.
al lado de = next to/beside (near-synonym, slightly less tight contact).
cerca de = near, not necessarily adjacent.
en (la entrada) = at/in the entrance area (location inside/at the threshold, not “next to”).

Why is it junto a la entrada and not junta a la entrada?

Because junto a is a fixed compound preposition and does not change form. The agreeing adjective forms (junto/junta/juntos/juntas) are used only when modifying nouns: e.g., las sillas juntas “the chairs together.”

Could I say en la entrada or a la entrada instead of junto a la entrada?

Yes, with nuance:

en la entrada = at/in the entrance area.
a la entrada (del supermercado) = at the entrance to the supermarket; can also mean “upon entering” in some contexts.
junto a la entrada stresses adjacency next to the entrance.

Why del supermercado and not de el supermercado? And when do I use al vs a la?

Spanish contracts:

de + el → del (hence del supermercado).
a + el → al; but with feminine nouns it’s a la (e.g., a la entrada). So you’d say junto al supermercado but junto a la entrada.

How would I say it in the past (“she left the cart”)? What about habitual past?

Completed past: Mi amiga dejó el carrito… (note the accent in dejó).
Habitual/ongoing past: Mi amiga dejaba el carrito…

How do I replace el carrito with a pronoun?

Use the masculine direct object pronoun lo:

Mi amiga lo deja junto a la entrada… Placement:
Before a conjugated verb: lo deja
Attached to infinitive/gerund/affirmative imperative: dejarlo, dejándolo, ¡Déjalo!

Does amiga mean “friend” or “girlfriend”? What if the friend is male?

amiga = female friend; amigo = male friend.
novia = girlfriend; novio = boyfriend. So “my girlfriend” is mi novia, not mi amiga.

What’s the difference between dejar and dejarse?

dejar + objeto = intentionally put/leave something somewhere.
dejarse + objeto = leave something behind by accident/forget it.
Example: Mi amiga se deja el carrito = she forgets the cart.

Would puerta work instead of entrada?

Yes, with nuance:

la entrada = the entrance/entry area.
la puerta = the physical door.
If you mean right by the doorway, junto a la puerta works; for the general entrance area, (junto) a/en la entrada is better.

Is súper a common short form of supermercado?

Yes. In Spain, the colloquial short form is el súper (with an accent). Your sentence could become: Mi amiga deja el carrito junto a la entrada del súper.