Shakespear is a proper name and should always be capitalized. Sonnets should not be unless it is a book title.
The title "Shakespeare's Sonnets" should be capitalized because it is a proper noun and the title of a specific work by William Shakespeare.
Earth, as in we live on the planet Earth, is supposed to be capitalized. Earth, as in the dirt we walk on, is not supposed to be capitalized.
Usually, yes a phase of the moon is supposed to be capitalized.
No, it shouldn't be capitalized.
No it shouldn't be capitalized.
Yes, "Hindenburg" should be capitalized as it is a proper noun referring to the German airship LZ 129 Hindenburg.
Yes, America should be capitalized.
no
No, but the names of individual languages are capitalized.
Yes, Siamese would be capitalized.
Yes.
Yes.
No.