Learn Farsi: ما داخل یک پارک تمیز هستیم.

In Farsi, the noun comes before the adjective that describes it. They are linked by a short 'e' sound called the Ezafe. Here, the noun park connects to the adjective tamiz (clean) to form park-e tamiz. This 'e' sound usually isn't written in the Persian script, but you always pronounce it.

Why does the word dakhel (inside) also need an Ezafe sound here?

Many Farsi position words act a bit like nouns and need an Ezafe to connect to the place that follows them, translating roughly to 'inside of'. Here, you say dakhel-e to connect it to yek park (a park).

If adjectives come after the noun, why does yek (a/one) come before park?

Numbers and quantities are an exception to the noun-first rule. Because yek tells us how many parks there are, it goes right before the noun, just like in English. Notice that we do not use an Ezafe between yek and park.

Could we leave out the word ma (we) at the beginning of the sentence?

Yes! In Farsi, the verb ending tells you who is doing the action. The -im ending on the verb hastim already means 'we are'. Dropping the pronoun ma is very common and sounds completely natural in spoken Farsi.