Η ανηφόρα μέχρι το χωριό είναι κουραστική, αλλά η κατηφόρα είναι πιο εύκολη.

They mean:

• η ανηφόρα = the uphill / the climb / the way up
• η κατηφόρα = the downhill / the descent / the way down

These are very common Greek nouns. In everyday Greek, they can refer both to:

• a road/path that goes up or down, and
• the act or experience of going uphill or downhill.

So in this sentence, η ανηφόρα μέχρι το χωριό means the uphill stretch up to the village, and η κατηφόρα means the downhill stretch.

Because both ανηφόρα and κατηφόρα are feminine singular nouns.

Greek definite articles change depending on gender, number, and case. Here:

• η = the for feminine singular in the nominative case

So:

• η ανηφόρα
• η κατηφόρα

Both are the subjects of their clauses, so nominative is used.

Because it agrees with η ανηφόρα, which is feminine singular.

In Greek, adjectives must agree with the noun they describe in:

• gender
• number
• case

So:

• η ανηφόρα → feminine singular
• κουραστική → feminine singular

If the noun were masculine or neuter, the adjective would change form. For example:

• ο δρόμος είναι κουραστικός = the road is tiring
• το περπάτημα είναι κουραστικό = the walking is tiring

Here, κουραστική matches ανηφόρα.

For the same reason: it agrees with η κατηφόρα, which is feminine singular.

So:

• η κατηφόρα = feminine singular
• εύκολη = feminine singular adjective

The phrase πιο εύκολη means easier.

μέχρι το χωριό means up to the village / as far as the village.

• μέχρι = until / up to / as far as
• το χωριό = the village

After μέχρι, Greek commonly uses the accusative, so:

• το χωριό is accusative singular

For this noun, το χωριό looks the same in nominative and accusative, so there is no visible change.

Examples:

• μέχρι την πόλη = up to the city
• μέχρι το σπίτι = up to the house

είναι means is.

It is the 3rd person singular form of the verb είμαι = to be.

So:

• Η ανηφόρα ... είναι κουραστική = The uphill ... is tiring
• η κατηφόρα είναι πιο εύκολη = the downhill is easier

Greek has two common ways to make comparatives:

1. πιο + adjective
2. a synthetic comparative form, often ending in -ότερος/-ότερη/-ότερο

So both of these can mean easier:

• πιο εύκολη
• ευκολότερη

In modern everyday Greek, πιο + adjective is extremely common and often sounds more natural in conversation.

So:

• η κατηφόρα είναι πιο εύκολη = the downhill is easier

This is a very normal choice.

It is understood from the context.

The sentence says:

• The uphill to the village is tiring, but the downhill is easier.

So πιο εύκολη means easier than the uphill even though Greek does not explicitly repeat it.

If you wanted to make it fully explicit, you could say something like:

• η κατηφόρα είναι πιο εύκολη από την ανηφόρα
  = the downhill is easier than the uphill

But in the given sentence, Greek leaves that comparison implied, just as English often does.

Because Greek often omits repeated information when it is already clear.

The first clause gives the setting:

• Η ανηφόρα μέχρι το χωριό...

Then the second clause simply contrasts it with:

• αλλά η κατηφόρα...

The listener naturally understands that the downhill is the corresponding downhill stretch, probably from the village or on the same route. Greek avoids repetition when the meaning is obvious.

English does this too:

• The climb to the village is tiring, but the descent is easier.

αλλά means but.

It is a very common conjunction used to contrast two ideas:

• κουραστική = tiring
• αλλά = but
• πιο εύκολη = easier

So the sentence contrasts the difficulty of going up with the relative ease of going down.

Here, tiring is the better translation.

κουραστικός / κουραστική / κουραστικό usually means:

• tiring
• exhausting
• sometimes wearisome

It can occasionally mean something like annoying or a drag, depending on context, but here the physical meaning is clearly intended:

• Η ανηφόρα ... είναι κουραστική
  = The uphill stretch is tiring.

το χωριό means the village.

The noun χωριό is neuter singular. In this sentence it refers to a specific village known from context.

Forms:

• το χωριό = the village
• ένα χωριό = a village

Because the article το is used, the speaker means a particular village, not just any village.

The structure is:

• Η ανηφόρα μέχρι το χωριό = subject phrase
• είναι = verb
• κουραστική = predicate adjective
• αλλά = but
• η κατηφόρα = second subject
• είναι = verb
• πιο εύκολη = predicate adjective

So very literally:

• The uphill up to the village is tiring, but the downhill is easier.

This is a very natural Greek word order. Greek is somewhat flexible with word order, but this version is neutral and clear.

A rough pronunciation guide is:

ee anee-FOR-a MEEHri to ho-ree-O EEne koo-ra-STEE-kee, a-LA ee ka-tee-FOR-a EEne PYO EV-ko-lee

A few notes:

• η / ι / ει / οι / υ all sound like ee
• χ in χωριό is like a soft throaty sound, somewhat like the ch in German Bach or Scottish loch
• Stress matters in Greek:
  • ανηφόρα
  • χωριό
  • κουραστική
  • κατηφόρα
  • εύκολη

Yes, but the meaning changes slightly depending on context.

With the article:

• η ανηφόρα = the uphill
• η κατηφόρα = the downhill

Without the article:

• ανηφόρα can mean uphill more generally
• κατηφόρα can mean downhill more generally

For example:

• Πηγαίνουμε ανηφόρα. = We’re going uphill.
• Ο δρόμος είναι κατηφόρα. = The road is downhill.

In your sentence, the article is used because it refers to a specific uphill stretch and a specific downhill stretch.

It can suggest both, which is very natural in Greek.

• Η ανηφόρα ... είναι κουραστική can mean the uphill stretch itself is tiring
• In practice, that also implies that going up it is tiring

Likewise:

• η κατηφόρα είναι πιο εύκολη means the downhill stretch is easier, that is, going downhill is easier

Greek often uses these nouns in a way that blends the route and the experience of taking it. The exact nuance comes from context.