As calças de ganga estão molhadas depois da chuva.

In Portuguese, every noun has a grammatical gender.

• calça (trousers, pant) is feminine: a calça
• In the plural, it becomes as calças (trousers / pants)

So you must use the feminine plural article as, not the masculine plural os.

Portuguese treats items like trousers/pants as inherently plural:

• as calças = trousers / pants (always plural in normal use)
• You almost never say a calça for a single leg; it sounds odd in everyday speech.

If you really want to emphasize “one pair,” you might say:

• um par de calças = a pair of trousers

But the normal way is simply plural as calças.

ganga is the European Portuguese word for denim.

• calças = trousers
• de ganga = made of denim

So calças de ganga literally means “trousers made of denim,” which corresponds to “jeans” in English.

In everyday European Portuguese:

• calças de ganga ≈ “jeans”

In Brazilian Portuguese, you’re more likely to hear:

• calça jeans or uma calça jeans.

When you talk about what something is made of, Portuguese uses the material in the singular:

• uma mesa de madeira = a wooden table
• um anel de ouro = a gold ring
• calças de ganga = denim trousers / jeans

So ganga stays singular because it names the material, not individual “denims.”

Portuguese uses:

• estar for temporary states or conditions
• ser for permanent or defining characteristics

Being wet after the rain is a temporary condition, so you use estar:

• As calças de ganga estão molhadas. = The jeans are (currently) wet.

If you said são molhadas, it would sound like “they are (by nature) wet,” which is strange for trousers.

The verb must agree in number with the subject:

• Subject: as calças de ganga → plural
• Therefore: estão (3rd person plural of estar)

If the subject were singular, you’d use está:

• O casaco está molhado. = The coat is wet.
• As calças estão molhadas. = The trousers are wet.

Adjectives in Portuguese agree with the noun in gender and number:

• Noun: as calças → feminine plural
• Adjective: molhado (wet) must change to feminine plural molhadas

Patterns:

• masculine singular: molhado
• feminine singular: molhada
• masculine plural: molhados
• feminine plural: molhadas

So: as calças (fem. pl.) estão molhadas (fem. pl.)

molhadas is the standard word for wet or damp, without extra nuance.

If you want to say “soaked” or “drenched,” you might use:

• encharcadas = soaked/drenched
• ensopadas = soaked (often used with clothes, food in sauce, etc.)

So:

• As calças estão molhadas. = The trousers are wet (maybe just somewhat).
• As calças estão encharcadas. = The trousers are completely soaked.

Portuguese usually contracts prepositions with articles.

• depois de
  • a chuva → depois da chuva

Here:

• de (of/after) + a (the, feminine singular) = da

So depois da chuva literally = “after the rain.” Writing depois de a chuva is grammatically wrong in standard Portuguese.

Using the definite article a often makes the event more specific:

• depois da chuva = after the rain (e.g., the rain that just happened / that we know about)
• depois de chuva (without the article) is possible but much less common here, and would feel more generic, like “after rain (in general).”

In everyday speech, depois da chuva is the natural, idiomatic choice for “after the rain.”

Yes, grammatically:

• depois da chuva
• após a chuva

Both mean after the rain.

Differences:

• depois de/da is more common and neutral in everyday speech.
• após sounds a bit more formal or written, but it’s not wrong in speech.

Yes. Both word orders are correct:

• As calças de ganga estão molhadas depois da chuva.
• Depois da chuva, as calças de ganga estão molhadas.

Starting with Depois da chuva simply emphasizes the time frame (“After the rain…”). It’s similar to English:

• “The jeans are wet after the rain.”
• “After the rain, the jeans are wet.”

In European Portuguese, people normally say:

• calças de ganga = jeans

The English word jeans is also understood, but it’s less common and can sound more informal or trendy, depending on context. Many speakers will just stick to calças de ganga in everyday speech.

A few key points (European Portuguese):

• calças → roughly KAL-sas
  
  • first ç is an /s/ sound, not /k/
  • final -s in EP sounds like /ʃ/ (“sh”) when followed by a consonant: calça[sh] de
• de is often very reduced and sounds like a quick d(ə).
• ganga → GUN-guh (both g are hard, like in English go).

Together in natural speech, it often flows like:
cálça-sh d’ gán-ga.