"That is it!"
Translation:To je ono!
I must agree with you. I used to have problems with the "tak" (and sometimes I still have) 'cause it has many uses depending on the context. But the diference i've been told is in the use, when they achieve something or when they succesfully did something. Example: when i was moving in, some friends help me move mi forniture and when they put it in a place that they like it, they shouted: "Tak!"