I am not in defence of but actually annoyed by:

Using if instead of whether. For example: "I will check if the window is open". This means: "if the window is open, I will check". What people mean to say is "I will check whether the window is open".

Also, using was in hypotheticals instead of the correct were. For example: if I were going to check whether the window was open, I wouldn't be standing here. Not "if I was going to check [...]".

All of them, unless there's need to be accurate.

Anything is acceptable if it's for comedic effect.

Its efficiency ‘hello’ to me is an empty word. But I am not going to say, “How do you do?” to someone to start a conversation. so saying, ‘howdy’ is the hill I am dying on.