El pes és dins de l'armariet.

És is the 3rd person singular of ser, meaning is.

The accent is important because és and es are different words in Catalan:

• és = is
• es = a reflexive/pronominal form, like himself / herself / itself / oneself in some contexts

So in this sentence, és must have the accent.

This is a very common question for English speakers, especially if they also know Spanish.

In Catalan, ser is often used for simple location, where Spanish would usually prefer estar. So El pes és dins de l'armariet is a normal way to say that the object is there.

Very roughly:

• ser can state where something is, as a simple fact
• estar can also appear in Catalan, but it often adds a nuance of state, situation, or placement

So here, és is perfectly natural.

Dins de means inside or inside of.

So:

• dins de l'armariet = inside the small cupboard / little cabinet / locker

It is a very common Catalan expression for being physically inside something.

Because the normal expression is dins de + noun.

So Catalan says:

• dins de l'armariet

not just:

• dins l'armariet

This is one of those combinations you mostly just learn as a unit: dins de = inside.

Yes. Dins de and dintre de are both used and both mean inside.

So these are both possible:

• El pes és dins de l'armariet.
• El pes és dintre de l'armariet.

In many contexts, the difference is just stylistic or regional rather than a big change in meaning.

Because armariet begins with a vowel, and the article el gets apostrophized:

• el armariet → l'armariet

Since the preposition de comes before it, you get:

• de + l'armariet = de l'armariet

So the structure is:

• dins de
  • l'armariet

Good question, because l' can stand for either el or la before a vowel.

Here, armariet is masculine. The full form without apostrophe would be:

• el armariet

You usually learn the gender from the dictionary form or from seeing the noun with its full article in another context.

Armariet is a diminutive form of armari.

So:

• armari = cupboard, cabinet, wardrobe
• armariet = small cupboard, little cabinet, small locker

The ending -et often makes a noun sound smaller, and sometimes more familiar or affectionate.

So armariet suggests a smaller version of an armari.

Because pes is a masculine singular noun, so it takes el.

So:

• el pes = the weight

Even if English sometimes uses weight a bit differently depending on context, grammatically in Catalan pes is masculine, so el is the correct article.

A simple approximate pronunciation for English speakers is:

el pess es deens duh lar-muh-ree-ET

A few useful notes:

• pes sounds roughly like pess
• és sounds like ess
• dins sounds roughly like deens
• armariet is stressed at the end: ar-ma-ri-ET

Pronunciation varies by dialect, but that approximation will help you say it understandably.