"Something is not right."
Translation:Щось не так.
Так is an adverb meaning "so." For example, one could ask, "Я це правильно роблю?" and the answer could be "Саме так!" or "Just so!" Or, "Це ТАК робиться?" as in, "This is done like THIS?"
Just like the adjective такий means "such," i.e. Вона така розумна дівчина! (She is such a smart girl!), you could also say Вона так розумна! (She is so smart!)
A useful phrase if you think you've made a mistake: Вибачте, якщо щось було не так.
«Так» usually means 'yes' or 'this way', but it can also have a meaning 'correctly, in a correct way, right'. It usually has this meaning only when it's doesn't modify a verb or an adjective, and stands on its own.