Should I speak properly?

You need to break out of the idea that there is a single "proper" English. The thing to remember is that English has "registers": different styles for different circumstances.

The register for formal writing differs from that of conversational speech - it uses slightly different vocabulary and grammatical forms. Both registers are correct - in their place.

The problem with the example you give is that "To whom did you speak?" is in a highly formal register. Most people, even ones who did well in education, don't use "whom" forms in ordinary conversation, so it'll come across as very formal and pompous.

I think your best move is to use in conversation the forms that you hear other people using.

dont problem, it happens to a great style of human beings. it could in many cases take place if uv have been given too lots saliva on your mouth OR if ur mouth is dry. that doesnt help. yet i comprehend what u recommend by utilising the stuttering and tripping on words. its in many cases happens whilst uv have been given lots dealing with ur head, and your attempting to get all of it out besides the indisputable fact that it doesnt pop out desirable. lol dont problem approximately it. only attempt to take a seat back extra. as others have mentioned, only supply comments and tell little memories and stuff yet dont attempt to dominate the communique bcos u could experience worse if human beings word ur blunders. so administration ur speech and your p.c.. and you will with a bit of luck build some extra self belief and then it is going to all be a miles off reminiscence! stable success xxx

You could hire a "speech" coach if you want to. Most people don't speak the way they write, also they often write the way they speak.

Generally in communicating, the rules for written communication are more rigidly adhered to. Verbal rules are very lax and yes, to whom would give one pause. You will not be pilloried, just adjust your verbage to the audience.