Based on the amount of carbons you have in your carbon chain. Follow these rules:

1 Carbon - Methine
2 Carbons - Etheine
3 Carbons - Propane
4 Carbons - Butane
5 Carbons - Pentane
6 Carbons - Hexane
7 Carbons - Heptane
8 Carbons - Octane
9 Carbons - Nonene
10 Carbons - Decane

I don't guarantee I spelled it all right but I just post this to remind myself incase I need to look up real quickly cuz I'm horrible with memorizing this stuff.