Адмаўленне

У мяне сёння няма часу.

I have no time today.

<em>Няма</em>, not <em>не</em>, and the thing absent goes into the genitive: <em>час</em> becomes <strong>часу</strong>.

Ніхто нічога не ведае пра гэта.

Nobody knows anything about it.

Three negatives in one clause and all three are required. English would allow only one.

Мы ніколі не былі ў Белавежскай пушчы.

We have never been to the Bielaviezhskaja Pushcha.

<em>Ніколі</em> still needs <em>не</em>. The Bielaviezhskaja Pushcha is the last remnant of the primeval forest that once covered the plain, and home to the European bison.

Ты стаміўся? — Не, зусім не.

Are you tired? - No, not at all.

As a one-word answer, "no" is <strong>не</strong>. <em>Няма</em> would be wrong here: it says something is absent, not that the answer is negative.

На стале ні хлеба, ні солі.

On the table there is neither bread nor salt.

Repeated <em>ні</em> with the genitive. Bread and salt are what a Belarusian household traditionally meets a guest with, so the sentence reads as a pointed absence.