Help to understand "ona kratka nejsou"
Help to understand. I don't know English very well. I beg your pardon. So. "ona kratka nejsou" translates as "they are not short." "Ona" means: they, she, to her. How to understand "in which case"? Similarly, ti, ty, ta, to are translated as "those".
It all really depends on the context - I would compare it to the English word "back" - which can be adverb (Go back), verb (to back off), noun (my back hurts), etc.
In the case "Ona nejsou krátká" (the word order "Ona krátká nejsou" sounds a bit odd in most cases), the "ona" is a neutrum plural personal pronoun in nominative.
We might replace the pronoun with a noun - I am not sure about the context of the sentence, so let's say we're talking about some planks ("prkno" in Czech). The sentence would therefore be (with a definite article/demonstrative pronoun) - "Ta prkna nejsou krátká." (again - the subject is neutrum, plural nominative)
"Ona" is also feminine singular personal pronoun in nominative - representing either women (a girl, a woman, actress etc) or feminine nouns (for example flower - "květina"). An example of such sentence might be "Ona je krásná." (She is beautiful).
"Ti, ty, ta to" are demonstrative pronouns ("ukazovací zájmena" in Czech).
"Ti" refers to masculine plural nouns in nominative For example "Ti muži jsou mladí." (The men are young)
"Ty" refers to feminine pl. nouns in nom. and akk., or to masculine pl. nouns in akk. For example "Ty ženy jsou mladé." (The women are young), "Vidím ty ženy." (I can see the women. - Akk.) or "Vidím ty muže." (I can see the men. - also Akk.)
"Ta" refers to neutrum pl. nouns in nom. and akk., or feminine sg. nouns in nom. For example "Ta kuřata jsou mladá" (The chickens are young), "My sníme ta kuřata (We'll eat the chickens. - Akk.) or "Ta dívka je mladá." (The girl is young - fem. sg. nom.)
"To" refers to neutrum sg. nouns in nom. and akkusative For example "To kuře je mladé." (The chicken is young), or "Sníme to kuře." (We'll eat the chicken.)
See wikipedia - sections Osobní zájmena (personal pronouns) and Ukazovací zájmena (demonstrative pronouns) https://cs.wikipedia.org/wiki/%C4%8Cesk%C3%A1_z%C3%A1jmena
***In colloquial Czech - the pronoun "Ta", when referring to nouns in neutrum plural (in both nom. and akk.), is very often replaced by the pronoun "ty". Many people therefore say for example "Sníme TY kuřata." instead of "Sníme TA kuřata.".
Hope it helped :) (and sorry that our language is so complicated)
Wow. Thanks for the help. Your answered in detail. I will learn grammar. Incredible)) thank you
The difference between "They (plural it) are not short." and "She is not short". is in the verb form:
"They are not short." = "Ona krátká nejsou."
"She is not short." = "Ona krátká není."