Learn Polish: Wczoraj nie mogliśmy chodzić po mieście. - We could not walk around the city yesterday.

The preposition po has multiple meanings. While it often means "after" in a time context (like po pracy - after work), when used with a physical space like po mieście, it describes moving on the surface of or randomly around that area. It takes the Locative case in both of these situations.

The dictionary word for city is miasto. Why does it change so much to become mieście?

The preposition po requires the Locative case. To change miasto into its Locative form, the ending -o becomes -e. Because -e is a softening vowel, it forces the consonant group before it to change: st becomes ść. Additionally, the vowel a shifts to e, resulting in the tricky form mieście.

Why use the verb chodzić instead of iść for "to walk"?

Chodzić is a multidirectional verb of motion. It is used for walking without a single, specific destination, like wandering or strolling. Since they are walking randomly around the city (po mieście), there is no specific end point, making chodzić the perfect choice. You would use iść if they were walking directly to a specific place.

Does the form mogliśmy tell us anything about who is in the "we" group?