When to use the nominative case in a negative sentence

Sometimes I see my students using partitive when they should use the nominative case, also known as the basic form. You need the partitive in certain negative sentences, but not always. 

Here's where you need the partitive in a negative sentence: 

Negative possessive stucture:

• Minulla ei ole tätä kirjaa. - I don't have this book. 
• Miksi teillä ei ole autoa? - Why don't you (plural) have a car?

Negative object sentence:

• Minä en ole nähnyt tätä kirjaa. - I haven't seen this book. 
• Me emme tarvitse autoa. - We don't need a car.

Here's where you DON'T need the partitive:

Negative predicative sentence:

• Tämä ei ole se kirja, jota tarkoitin. - This is not the book that I meant.
• Tuo ei ole minun auto(ni). - That is not my car.

However, you need the partitive when talking about something uncountable:

• Onko tämä kahvia vai teetä? - Is this coffee or tea?

Related posts:

• Mikä or mitä?
• Describing things