Ciąża trwa dziewięć miesięcy.

Trwa is the 3rd person singular present-tense form of trwać, which means to last, to continue, or to go on.

So:

• trwać = to last
• trwa = lasts

It is 3rd person singular because the subject, ciąża, is singular.

Because Polish uses trwać for duration.

• Ciąża jest... would mean Pregnancy is...
• Ciąża trwa... means Pregnancy lasts...

So if you want to talk about how long something continues, trwać is the natural verb.

In Polish, with trwać, you normally just give the length of time directly.

So Polish says:

• Ciąża trwa dziewięć miesięcy.

Literally, that is closer to:

• Pregnancy lasts nine months.

English often inserts for, but Polish does not need it here.

Because after numerals 5 and higher, Polish normally uses the genitive plural form of the noun.

So:

• jeden miesiąc = one month
• dwa / trzy / cztery miesiące = two / three / four months
• pięć / sześć / dziewięć miesięcy = five / six / nine months

The noun miesiąc changes to miesięcy, which is its genitive plural form.

Miesięcy is genitive plural.

That happens because dziewięć belongs to the group of numerals that usually require the noun after them to be in the genitive plural.

So in dziewięć miesięcy:

• dziewięć = nine
• miesięcy = genitive plural of miesiąc

Ciąża is in the nominative singular because it is the subject of the sentence.

It is the thing doing the lasting:

• Ciąża = pregnancy
• trwa = lasts

So ciąża is the grammatical subject.

Because Polish has no articles.

English distinguishes:

• a pregnancy
• the pregnancy
• pregnancy in general

Polish does not use separate words for that. Context tells you what is meant.

So Ciąża trwa dziewięć miesięcy can be understood as a general statement about pregnancy.

Roughly, Ciąża sounds like CHON-zha, but that is only an approximation.

A few important points:

• Ci before a vowel gives a soft sound like Polish ć
• ą is a nasal vowel, somewhat like nasalized on
• ż sounds like the s in measure

Stress in Polish is usually on the second-to-last syllable, so here the stress falls on CIĄ:

• CIĄ-ża

This part is tricky for English speakers.

A rough guide:

• dziewięć ≈ something like דזשEV-yench, but with softer consonants
• miesięcy ≈ mye-SHYEN-tsy

A few useful pronunciation notes:

• w in Polish sounds like English v
• ć is a very soft consonant, somewhat like a softened ch
• ę often changes in actual pronunciation depending on the sound after it
  
  • in dziewięć, it is heard close to eń
  • in miesięcy, it is heard close to en

You do not need to pronounce ę as a strong nasal vowel in every position exactly as written.

The neutral, most natural order here is:

• Ciąża trwa dziewięć miesięcy.

Polish word order is more flexible than English, so other orders are possible, but they usually sound marked, emphatic, or less natural in ordinary speech.

For a basic learner, this standard order is the best one to use.

By itself, it is most naturally understood as a general fact.

So it works like:

• Pregnancy lasts nine months.

If you wanted to talk about a specific pregnancy, context would usually make that clear, or you might add a word like:

• Ta ciąża = this pregnancy

For example:

• Ta ciąża trwa już sześć miesięcy. = This pregnancy has already lasted six months.

Not necessarily. In everyday language, it is a normal general statement, not a piece of exact medical timing.

In more precise language, Polish speakers might say:

• około dziewięciu miesięcy = about nine months
• około czterdziestu tygodni = about forty weeks

So dziewięć miesięcy here is best understood as the standard general way of expressing the length of pregnancy.