Aquesta part és fàcil.

Aquesta is the feminine singular form of this in Catalan. It has to agree with the noun it modifies. Since part is a feminine singular noun, you use aquesta part.

The basic forms are:

• aquest = this (masculine singular)
• aquesta = this (feminine singular)
• aquests = these (masculine plural)
• aquestes = these (feminine plural)

So:

• aquest llibre = this book
• aquesta part = this part

Yes. In Catalan, grammatical gender is not always obvious from the ending. While many feminine nouns do end in -a, plenty do not. Part is a feminine noun, so it takes feminine words with it:

• aquesta part
• la part
• una part

This is something you often just have to learn with the noun.

Because aquesta already works as a determiner, like English this. In Catalan, you normally do not combine a demonstrative like aquesta with the definite article in this kind of sentence.

So Catalan says:

• aquesta part = this part

not:

• la aquesta part

És is the he/she/it form of the verb ser = to be.

So:

• és = is

The accent is important because it distinguishes és (is) from es, which is a different word used as a pronoun in many contexts.

Examples:

• Aquesta part és fàcil. = This part is easy.
• Es diu Maria. = Her name is Maria. / She is called Maria.

So the accent helps show that és is the verb.

Some Catalan adjectives have the same form for masculine and feminine singular. Fàcil is one of them.

So you get:

• un exercici fàcil = an easy exercise
• una part fàcil = an easy part

The plural does change:

• exercicis fàcils
• parts fàcils

So fàcil does agree in number, but not with a different masculine/feminine form in the singular.

The stress is on the first syllable: FÀ-cil.

The grave accent (à) shows both the stressed syllable and the vowel quality. For a learner, the most important point is: pronounce the stress on the first syllable, not on the second.

So:

• fàcil ≈ FAH-sil

A careful pronunciation is roughly:

a-KES-ta PART es FAH-sil

A more Catalan-like pronunciation would be approximately:

• aquesta → uh-KES-tuh / eh-KES-tuh depending on accent
• part → part
• és → es
• fàcil → FAH-sil

The main stresses are on:

• -ques- in aquesta
• part
• és
• fà- in fàcil

This is the normal and most neutral word order:

• Aquesta part és fàcil.

That is:

• subject: Aquesta part
• verb: és
• adjective/complement: fàcil

Catalan often uses the same basic order as English in simple statements like this. Other word orders are possible for emphasis, but this is the standard one learners should use first.

Yes, but only if the noun is already understood from context.

• Aquesta part és fàcil. = This part is easy.
• Aquesta és fàcil. = This one is easy.

In the second sentence, aquesta is acting more like this one, with part left out because it is obvious.

The plural would be:

Aquestes parts són fàcils. = These parts are easy.

Notice all the changes:

• aquesta → aquestes (feminine singular to feminine plural)
• part → parts
• és → són
• fàcil → fàcils

This is a good example of agreement across the sentence.

Yes. Part is used very much like English part. Depending on context, it can mean:

• a section of a text, book, class, or exam
• a portion of something
• a side or role in some contexts

So Aquesta part és fàcil could mean:

• this section is easy
• this part is easy

The exact nuance depends on the situation.