market
The German word 'Markt' is a noun that directly translates to 'market' in English. It is used to refer to a place where goods are bought and sold, such as a marketplace or a supermarket. It can also be used metaphorically to refer to a market in the economic sense, such as the stock market or the housing market.
I am going to the market
This sentence simply expresses an action that someone is taking, in this case, going to the market. The preposition 'auf' is used here to mean 'to' when indicating direction.
We meet at the market
In this example, the speaker is arranging a meeting with someone at the market. The sentence uses the reflexive 'uns' to refer to the speaker and the other person.
She works opposite the market
This sentence is telling us about the location of a person's workplace. The phrase 'gegenüber dem' is a preposition that means 'opposite the'.