Hello, dear student!
Most people, who learn the Russian language, even don't know that there are two categories of particles, which show an interlocutor that we speak about the negation or intensification of emotions and feelings. Today we will find out the difference between "не" and "ни".
Particle "не" [ne] not - expresses negation and it's written separately with most words
Не надо стесняться! [Ni nada stisnyat'sya] - Don't be shy!
Particle "ни" [ni] nor - serves to intensify the negation in a sentence, for example:
А в этой квартире ни души! [A f ekhtaj kvartire ni dushi] - And here is no one in this flat!
There can be sentences with double negation, it means that a sentence conveys positive meaning, as two negatives make an affirmative. For example:
Катя не могла не услышать звук этой музыки [Katya ni magla ni uslishat' zvuk ekhtaj muzyki] - Katya could not help but hear the sound of this music.
When you see or hear in a sentence the repeated usage of the particle "ни- ни", it means that it unites words in a sentence. Sometimes, you can omit the particle or replace it with the conjunction "и" (and).
Не видно было ни весёлых лиц, ни приятных улыбок. Все казалось серым. [Ni vidna byla ni visyolykh lits, ni priyatnykh ulybak. Fsyo kazalas' serym] - There were neither funny faces, no pleasant smiles. Everything seemed to be grey.
The particle "не" is often used in sentences in combination with the conjunction "пока" [paka] yet/still/until
Девочка сидела под деревом, пока её папа не вернулся [Devachka sidela pad derevam, paka eyo papa ni virnulsya] - A girl was sitting under the tree, until her father came back.
The particle "не" is also used in sentences with the word "чтобы", for example:
Чтобы не происходило с твоей жизнью, не сдавайся! [Shto by ni praiskhadila s tvaej zhizn'yu, ni sdavajsya!] - No matter what is going on with your life, never give up!
To express emotions and feelings in exclamatory sentences, you can also see the particle "не":
Она объехала весь мир! Где она только не бывала! [Ana ob''ekhala ves' mir! Gde ana tol'ka ni byvala!] - She travelled the whole world! There is almost no place that she didn't visit!