This is the 23rd most frequent Czech word.
jsme
"Jsme" means "we are" in English.
The word "jsme" is used here as the present indicative verb form of "být" (to be) for first-person plural, meaning 'we are.'
Jsme šťastní spolu.
We are happy together.
In this sentence, "jsme" is also an auxiliary verb for the past tense form "přijeli", relating to the first-person plural 'we arrived.'
Ačkoliv jsme přijeli pozdě, vše šlo hladce.
Although we arrived late, everything went smoothly.
Here, "jsme" functions as an auxiliary verb in the past tense construction of "viděli" indicating the first-person plural 'we have seen.'