Things that are difficult to say when you're drunk:

• Indubitably
• Innovative
• Preliminary
• Proliferation
• Cinnamon

Things that are very difficult to say when you're drunk:

• Specificity
• "Cogito ergo sum."
• British Constitution
• Passive-aggressive disorder
• loquacious
• transubstantiate

Things that are downright impossible to say when you're drunk:

• Thanks, but I don't want to have sex.
• No more for me, I've had enough to drink
• Sorry, but you're not really my type.
• Good evening, Officer. Isn't it lovely out tonight.
• Oh, I just couldn't, no one wants to hear me sing!

True, true

Another tough one for some reason

Cellular, that's why I shorten it to cell.