It depends what it stands for. If it's the Prime Minister, then yes. If you mean 2 p.m., then no.
"PM" is typically capitalized when it is used as an abbreviation for "post meridiem" or "prime minister".
PM is very much indeed capitilised.
"Can" is typically not capitalized in sentences unless it is the first word or part of a proper noun.
Yes, "I am" is typically capitalized because "I" is a pronoun and should always be capitalized in English.
Yes, "Spring 2009" should be capitalized because it is a specific season and year.
Yes, "Malaysian" is capitalized when referring to the nationality or language of Malaysia.
Yes, "Football" should be capitalized when referring to the sport in general.
No!
No. it's not necessary. Example: Let's have dinner at 7 p.m.
Yes. They are abbreviations for the Latin terms ante meridiem and post meridiem, and should therefore always be capitalized. Technically they should be spelled A.M. and P.M. for the same reason, but they are most often not and it is considered correct either way.
PM in time stands for "Post Meridiem" and refers to "after noon" in 12 hour clock. The "meridiem" is when the sun reaches its zenith (theortically at noon) and post means after.
Midnight to noon is 12 hours (AM), noon to midnight is another 12 hours (PM). Therefore, it is 12 hours from PM to AM.
It's neither, 12 noon and 12 midnight are just that although there are a lot of illiterates in positions where they should know better!)
No, seasons are not capitalized.
"Can" is typically not capitalized in sentences unless it is the first word or part of a proper noun.
Yes, "Spring 2009" should be capitalized because it is a specific season and year.
No, keywords do not have to be capitalized.
No it's not capitalized.
No it shouldn't be capitalized.