Η περίοδος ήταν δύσκολη.

Word by word:

• Η = the
• περίοδος = period
• ήταν = was
• δύσκολη = difficult

So the structure is very close to English: The period was difficult.

Η is the feminine singular nominative definite article, meaning the.

It is used because περίοδος is:

• singular
• feminine
• the subject of the sentence

Greek articles change depending on gender, number, and case, so you cannot use just one form of the for every noun.

This is a very common learner question.

In Greek, nouns ending in -ος are often masculine, but not always. Περίοδος is one of the nouns that is feminine even though it ends in -ος.

So you learn it as:

• η περίοδος = the period

The article helps you identify the gender. When learning nouns in Greek, it is best to memorize them together with the article.

Because adjectives in Greek must agree with the noun they describe.

Since περίοδος is:

• feminine
• singular
• nominative

the adjective must also be feminine singular nominative:

• masculine: δύσκολος
• feminine: δύσκολη
• neuter: δύσκολο

So:

• η περίοδος ήταν δύσκολη
• not η περίοδος ήταν δύσκολος
• not η περίοδος ήταν δύσκολο

Ήταν is the imperfect form of είμαι (to be).

In this sentence, it usually translates naturally as was.

Why imperfect? Because in Greek, the imperfect of είμαι is used for past states or conditions. English often just says was, but Greek uses ήταν for that past-state meaning.

Examples:

• Ήταν κουρασμένος. = He was tired.
• Η περίοδος ήταν δύσκολη. = The period was difficult.

It can sometimes suggest either, depending on context.

Most naturally here, Η περίοδος ήταν δύσκολη means:

• The period was difficult

But because ήταν is imperfect, in the right context it can also carry a sense like:

• The period used to be difficult
• That time was difficult

Usually, the surrounding context tells you which English translation sounds best.

Because Greek does not need a dummy subject like English often does.

In English, we sometimes say things like:

• It was difficult
• It is raining

Greek often does not need an extra it. In this sentence, the real subject is already there:

• Η περίοδος = the period

So nothing extra is needed.

Δύσκολη is in the nominative, because it is a predicate adjective linked to the subject by ήταν.

In Greek, after verbs like είμαι (to be), the adjective normally agrees with the subject in:

• gender
• number
• usually case as well

So both parts are nominative:

• η περίοδος → nominative feminine singular
• δύσκολη → nominative feminine singular

Yes. Greek word order is more flexible than English.

The neutral order here is:

• Η περίοδος ήταν δύσκολη.

But you could also say:

• Δύσκολη ήταν η περίοδος.

That version gives more emphasis to δύσκολη (difficult), a bit like:

• Difficult was the period
• or more naturally in English, The period was difficult indeed

So the original sentence is the most straightforward, but other orders are possible for emphasis.

A rough pronunciation guide:

• Η περίοδος ≈ ee PE-ree-oh-thos
• ήταν ≈ EE-tan
• δύσκολη ≈ THEES-ko-lee

A few notes:

• η / ή sounds like ee
• δ sounds like the th in this
• θ in περίοδος sounds like the th in think
• the accent marks show which syllable is stressed:
  • περίοδος
  • ήταν
  • δύσκολη

Not only.

Περίοδος can mean different things depending on context, including:

• a period of time
• a phase
• a school class period
• in some contexts, a menstrual period

In Η περίοδος ήταν δύσκολη, the most natural meaning is usually period/phase of time.

Normally, no—not in standard Greek for this meaning.

If you are talking about the period, you use the article:

• Η περίοδος ήταν δύσκολη.

Leaving out the article would sound unnatural here. Greek uses the definite article more regularly than English in many cases.

Greek accent marks show which syllable is stressed.

So:

• ήταν → stress on the first syllable
• δύσκολη → stress on the first syllable
• περίοδος → stress on ρί

These marks are an important normal part of Greek spelling, not optional decoration. They help with both pronunciation and correct writing.