Si vostè vol cuidar les plantes del seu pati, primer ha de mirar si la gespa necessita aigua.

Vostè is the formal singular word for you in Catalan, similar to Spanish usted. It is used for politeness, distance, or respect.

So:

• Si vostè vol... = If you want... (formal)
• Si tu vols... = If you want... (informal)

A learner may notice that vostè takes a third-person verb form, not a second-person one. That is normal in Catalan:

• vostè vol
• not vostè vols

Because vostè grammatically behaves like a third-person singular subject, even though it means you.

Compare:

• tu vols = you want (informal)
• vostè vol = you want (formal)
• ell/ella vol = he/she wants

So vol is the correct form with vostè.

Cuidar means to take care of, to look after, or to care for.

After verbs like voler (to want), Catalan normally uses an infinitive, just like English:

• vol cuidar = wants to take care of

So:

• vostè vol cuidar les plantes = you want to take care of the plants

Les is the feminine plural definite article, meaning the.

Catalan articles change according to gender and number:

• el = the (masculine singular)
• la = the (feminine singular)
• els = the (masculine plural)
• les = the (feminine plural)

Since plantes is feminine plural, the article must be les:

• les plantes = the plants

Del is a contraction of de + el:

• de = of / from
• el = the
• del = of the / from the

So:

• del seu pati literally means something like of your patio

Also, seu means your here because it agrees with the noun pati, which is masculine singular.

Breakdown:

• pati = patio / yard
• el seu pati = your patio
• les plantes del seu pati = the plants of your patio / the plants in your patio

In natural English, this is usually just the plants in your yard/patio.

Catalan possessives agree with the thing possessed, not with the person who possesses it.

Here, pati is masculine singular, so the possessive is seu:

• el seu pati = his/her/your(formal) patio

Other forms include:

• la seva planta = his/her/your(formal) plant
• els seus patis = his/her/your(formal) patios
• les seves plantes = his/her/your(formal) plants

So seu matches pati, not vostè.

Yes — it can mean any of those, depending on context.

Seu / seva / seus / seves can mean:

• his
• her
• your (formal)
• sometimes its

In this sentence, because the subject is vostè, the natural interpretation is your patio.

Catalan often relies on context for this. If a speaker wants to avoid ambiguity, they may use a fuller expression such as:

• el pati de vostè
• el pati d’ell
• el pati d’ella

But in normal usage, el seu pati is very common.

Ha de means has to, must, or sometimes should, depending on context.

It comes from:

• ha = has
• de
  • infinitive = to / must / have to construction

So:

• ha de mirar = has to look, must check, or should check

With vostè, this still uses the third-person singular form:

• vostè ha de mirar

In Catalan, one common way to express obligation is:

• haver de + infinitive

So:

• ha de mirar = has to look / needs to check
• he de marxar = I have to leave
• hem de parlar = we have to talk

The de is just part of the standard structure. You usually cannot leave it out.

Mirar literally means to look, but very often it also means to check or to see.

So mirar si... means:

• to check whether...
• to see if...

In this sentence:

• primer ha de mirar si la gespa necessita aigua = first you have to check if / whether the lawn needs water

This is a very common Catalan pattern.

They are the same word, but they do different jobs here.

1. Si vostè vol...

   • here si means if
   • it introduces a condition

2. mirar si la gespa necessita aigua

   • here si means if / whether
   • it introduces an indirect yes/no question

So the first si is conditional, and the second si is more like whether.

English also does this:

• If you want..., first check if the lawn needs water.

Gespa means grass or lawn, depending on context.

In this sentence, because it is something that may need watering in a yard or patio, the lawn is the most natural translation.

It is a feminine singular noun:

• la gespa = the grass / the lawn

In Catalan, when talking about a substance in a general sense, you often do not use the article.

So:

• necessita aigua = needs water

This is similar to English, where we also normally say needs water, not needs the water.

You could use an article in a more specific context, but here the general form without an article is the normal one.

Primer means first. It is being used as an adverb here.

Catalan often places adverbs like this before the verb phrase:

• primer ha de mirar = first, you have to check

This word order is very natural in Catalan. English does something similar:

• First, you have to check...

Yes. Catalan often omits subject pronouns because the verb form usually makes the subject clear from context.

So this would also be possible:

• Si vol cuidar les plantes del seu pati, primer ha de mirar si la gespa necessita aigua.

However, including vostè can make the sentence clearer, more formal, or more emphatic.

A natural informal version would be:

• Si vols cuidar les plantes del teu pati, primer has de mirar si la gespa necessita aigua.

Changes:

• vostè → usually omitted, but would correspond to tu
• vol → vols
• seu → teu
• ha de → has de

So the grammar shifts from formal third-person forms to informal second-person forms.