Learn Hardcore Spanish (Spain): El dueño de la granja usa un tractor grande, así que tenemos que ir con cuidado en la carretera. - The owner of the farm uses a big tractor, so we have to be careful on the road.

dueño is more common in everyday speech and can feel slightly more personal or informal.
- el dueño de la granja – the farm’s owner
propietario sounds a bit more formal, legal, or technical.
- el propietario de la finca – the property owner (e.g. in legal documents)

In this sentence, dueño is natural and idiomatic; propietario would also be correct, just a bit more formal.

Why la granja and not la finca or el rancho in Spain?

In Spain:

granja usually refers to a farm, often with animals (dairy farm, chicken farm, etc.).
finca is more like a piece of land / estate / property. It might have a house, crops, or nothing. It doesn’t necessarily mean “farm”.
rancho is not the normal word for “farm” in Spain; it sounds more Latin American or specifically Mexican in many contexts.

For farm (Spain), la granja is the most straightforward, especially if we imagine a place with animals or agricultural activity.

Why is it usa and not está usando for “uses a big tractor”?

Both are grammatically possible but mean different things:

usa un tractor grande (present simple)
- Describes a habitual or general fact: The owner (normally) uses a big tractor.
está usando un tractor grande (present continuous)
- Describes something happening right now: The owner is using a big tractor (at this moment).

In the sentence, we are describing a general situation that explains why we must be careful on the road, so the present simple (usa) is more natural.

Could I say utiliza instead of usa? Is there a difference?

Yes, you can say:

El dueño de la granja utiliza un tractor grande…

usa and utiliza both mean uses, but:

usa is more common, shorter, and more neutral in everyday speech.
utiliza can sound a bit more formal or technical.

In normal spoken Spanish in Spain, usa is probably the default choice here.

Why is it un tractor grande and not un grande tractor or un gran tractor?

In Spanish, most adjectives come after the noun:

un tractor grande = a big tractor (neutral meaning)

un grande tractor is incorrect; you don’t place grande there in that full form.

However, gran (short form of grande) can go before the noun, but it often adds a more emotional or figurative nuance:

un gran tractor could mean a great / impressive tractor, not just physically big.

So:

un tractor grande – focuses on size.
un gran tractor – suggests it’s impressive, powerful, very good, etc.

What does así que mean here, and how is it different from entonces or por eso?

así que is a conjunction meaning roughly “so” / “therefore”, introducing a result or consequence:

…usa un tractor grande, así que tenemos que ir con cuidado…
- …he uses a big tractor, so we have to be careful…

Compared to others:

entonces – often used as “then / so”, but more like a discursive connector. It can sound less clearly causal.
por eso – literally “because of that / that’s why”, also shows cause–effect.

You could say:

…usa un tractor grande, por eso tenemos que ir con cuidado… – also fine.
But así que is very natural conversational Spanish to express a consequence.

Why do we say tenemos que ir con cuidado instead of just tenemos cuidado?

Several points:

tener que + infinitive expresses obligation / necessity:
- tenemos que ir con cuidado = we have to go carefully / we must be careful while going/traveling.
tener cuidado by itself means to be careful, but you don’t normally say tenemos cuidado as a command or obligation to yourself. You’d say:
- tenemos que tener cuidado – we have to be careful
- ten cuidado – be careful (to one person)
ir con cuidado is an idiomatic way to say:
- to go carefully / to proceed with caution, especially about moving, driving, or walking.

So the sentence focuses on how we move on the road, so ir con cuidado is a good match.

What is the difference between ir con cuidado and tener cuidado?

Both are common and correct, but:

ir con cuidado
- Literally: to go with care.
- Emphasizes the manner of moving (driving, walking, riding a bike).
- Very natural with movement verbs and in traffic situations.
- Tenemos que ir con cuidado en la carretera.
tener cuidado
- Literally: to have care.
- More general “to be careful”, not only about movement.
- Also fine in this context:
  - Tenemos que tener cuidado en la carretera.

In this sentence, ir con cuidado slightly highlights the idea of driving / moving along the road carefully.

Why is it en la carretera and not por la carretera?

Both can appear in similar contexts, but the nuance differs:

en la carretera = on the road
- Focus on location: where we are / where the situation happens.
- Tenemos que ir con cuidado en la carretera – We must go carefully while on the road.
por la carretera often means along / through the road or describes the route:
- Vamos por la carretera – We’re going along the road.
- Conduce por la carretera principal – Drive along the main road.

In this sentence, we’re talking about how we must behave when we’re on the road, so en la carretera is very natural.
You could also say por la carretera and it wouldn’t be wrong; it would just sound a bit more like talking about the route than the location.

Why do we use a comma before así que in Spanish?

Spanish often uses a comma before conjunctions that introduce a result or consequence, such as así que, por lo tanto, de modo que, etc.

…usa un tractor grande, así que tenemos que ir con cuidado…

The comma marks a slight pause and separates:

The cause / reason: El dueño de la granja usa un tractor grande
The consequence: así que tenemos que ir con cuidado en la carretera

In informal writing, you sometimes see it without a comma, but the comma is standard and recommended.

Is there anything special about the adjective grande in Spanish?

Yes, grande has a special short form gran:

Position:
- After the noun: un tractor grande – a big tractor (physical size).
- Before the noun (short form): un gran tractor – a great / impressive tractor.
Form:
- Before a singular noun, grande usually becomes gran:
  - gran casa, gran ciudad, gran tractor.

So, in your sentence:

un tractor grande – neutral description of size.
If you said un gran tractor, you’d be implying it’s excellent / impressive, not just big.