Po koncertu jsme šli domů.

Here po means after.

With this meaning, po is followed by the locative case in Czech. So:

• po koncertu = after the concert

This is a very common pattern:

• po obědě = after lunch
• po škole = after school
• po práci = after work

Be careful: po can have other meanings in other contexts, but in time expressions like this, after is the key idea.

Because koncert has to change form after po.

The basic dictionary form is:

• koncert = concert

But after po, Czech requires the locative singular, and for this noun that form is:

• koncertu

So:

• koncert → nominative
• po koncertu → locative after the preposition po

This kind of case change is one of the biggest differences from English: Czech nouns often change endings depending on their role in the sentence.

This is the normal Czech past tense structure.

Czech past tense is usually made with:

• a past participle
• plus a form of být (to be)

Here:

• jsme = we are / we have as an auxiliary in past tense
• šli = past participle of jít / related motion verb meaning went

Together:

• jsme šli = we went

Other examples:

• šel jsem = I went
• šla jsem = I went (said by a woman)
• šli jsme = we went

So even though English just says we went, Czech builds it more like we have-went, structurally speaking.

Yes, that depends on who “we” are.

• šli is used for:

  • a group of men
  • a mixed group of men and women
  • sometimes a group of unknown gender in a neutral/default way

• šly is used for:

  • a group of only women

So:

• Po koncertu jsme šli domů. = said by men, or a mixed group
• Po koncertu jsme šly domů. = said by a group of women

This is because Czech past tense agrees with the gender/number of the subject.

Because Czech often drops subject pronouns when they are not needed.

The verb form jsme already tells you the subject is we, so my is usually unnecessary.

That means:

• Po koncertu jsme šli domů. = normal
• Po koncertu my jsme šli domů. = possible, but more emphatic

You would add my only if you want contrast or emphasis, for example:

• Oni šli do restaurace, ale my jsme šli domů.
  • They went to a restaurant, but we went home.

Because domů expresses movement toward home, while doma means at home.

• domů = homeward, to home
• doma = at home

So:

• Jsme šli domů. = We went home.
• Byli jsme doma. = We were at home.

This is a very important distinction in Czech: one form for direction, another for location.

Because domů is a very common adverb meaning home in the sense of to one’s home.

Czech often uses domů instead of a more literal phrase like do domu.

The difference is roughly:

• domů = home, to one’s home
• do domu = into the house/building

So in this sentence, domů is the natural choice if the meaning is simply that the people went home.

For example:

• Po práci jdu domů. = After work I go home.
• Jdu do domu. = I’m going into the house.

No, Czech word order is fairly flexible.

This sentence is a very natural, neutral order:

• Po koncertu jsme šli domů.

But other word orders are possible, depending on emphasis:

• Šli jsme domů po koncertu.
• Domů jsme šli po koncertu.

The meaning stays basically the same, but the focus shifts a little.

The version with Po koncertu first is very natural if you want to set the time frame first: After the concert, ...

These two words often look difficult to English speakers.

A rough guide:

• jsme ≈ ys-meh or very reduced in natural speech
• šli ≈ shli

A few details:

• š sounds like English sh
• í is a long ee
• j in Czech sounds like English y

In careful pronunciation, jsme has the j sound, but in fast everyday speech it may be reduced, so learners sometimes feel it is hard to hear clearly.

Yes. This is one of those verbs where the forms are not very predictable at first.

The infinitive is:

• jít = to go

But the past forms use šel / šla / šli / šly:

• šel = he went
• šla = she went
• šli = they/we went (masculine or mixed)
• šly = they/we went (all-female)

So yes, šli belongs with jít, even though the form changes a lot. This is something you mostly just have to learn and get used to.