Aquestes patates fregides tenen bon gust, però són una mica salades.

Because patates is a feminine plural noun, and the demonstrative has to agree with it.

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

So:

• aquestes patates = these potatoes / these fries

In Catalan, many descriptive adjectives usually come after the noun, especially when they classify or describe what kind of thing it is.

So:

• patates fregides = fried potatoes / fries / chips

This is more natural than putting fregides first. In this expression, fregides is functioning almost like part of the name of the food.

Because the adjective must agree with patates.

• patata is feminine singular
• patates is feminine plural

So the adjective also becomes feminine plural:

• fregit = fried, masculine singular
• fregida = fried, feminine singular
• fregits = fried, masculine plural
• fregides = fried, feminine plural

That is why you get patates fregides.

It can depend on context and region.

Very often, patates fregides means fries. But in some contexts it can also refer more generally to fried potatoes, and people may use it for packaged potato chips/crisps too.

If you want to be more specific, you may also see:

• patates xips = crisps / potato chips
• patates fregides = fries / fried potatoes

So this sentence could sound like it is talking about fries, but context matters.

Yes. tenir bon gust is a very natural way to say that food tastes good.

Literally, it means to have good taste/flavor, but in Catalan it is commonly used for food. So:

• Aquestes patates fregides tenen bon gust = These fries taste good

Be careful: in English, have good taste often means good judgment in art, fashion, etc. In Catalan, tenir bon gust can refer very naturally to flavor.

Because bo changes to bon before a masculine singular noun.

So:

• bo = good
• bon = good, before a masculine singular noun

Since gust is masculine singular, Catalan uses:

• bon gust

This is similar to other common phrases like:

• un bon llibre = a good book
• bon dia = good morning / hello

Both relate to taste/flavor, but they are not always used in exactly the same way.

• gust often refers to taste in a broad sense, and it appears in common expressions like tenir bon gust
• sabor is often closer to flavor

In this sentence, bon gust sounds very natural and idiomatic. You could talk about el sabor of something too, but tenir bon gust is a common everyday way to say food tastes good.

Catalan often uses ser to describe a quality or characteristic of something, including taste-related qualities.

So:

• són una mica salades = they are a bit salty

This presents saltiness as a property of the fries. In everyday speech, some speakers may also use estar in certain contexts, especially when focusing on the current result, but ser salat / ser dolç / ser amarg is very normal when describing flavor.

So the sentence’s són is perfectly natural.

Una mica means a little or a bit.

So:

• són una mica salades = they are a bit salty

It is a very common expression and can be used with adjectives, adverbs, and sometimes verbs:

• una mica cansat = a little tired
• parla una mica ràpid = he/she speaks a bit fast

Again, it is adjective agreement. Salades has to match patates, which is feminine plural.

Forms:

• salat = salty, masculine singular
• salada = salty, feminine singular
• salats = salty, masculine plural
• salades = salty, feminine plural

So:

• patates salades
• Aquestes patates fregides... són una mica salades

The accent marks the stressed vowel and helps distinguish the word’s pronunciation.

• però = but

The stress falls on the second syllable: pe-RÒ.

This is a very common conjunction in Catalan. The accent is part of the normal spelling, so it always has to be written that way.

Catalan adjective position is flexible, but some patterns are very common.

• fregides comes after patates because it is a descriptive/classifying adjective: fried potatoes
• bon comes before gust because bo/bona often goes before the noun in common expressions like bon gust, bon dia, bon moment

So both orders are natural, but for different reasons:

• patates fregides
• bon gust

This is something you gradually get used to through exposure, because adjective placement in Catalan is not always the same as in English.

You would need to change all the words that agree with patata.

Singular version:

• Aquesta patata fregida té bon gust, però és una mica salada.

Notice the changes:

• aquestes → aquesta
• patates → patata
• fregides → fregida
• tenen → té
• són → és
• salades → salada

This is a good way to see how much agreement Catalan uses.