When referring to the planet, then it's "Earth". If referring to ground or dirt, it's "earth".
No, not always. Earth as the planet, yes. "Go out and dig in the earth" no.
In most cases this is interpreted as referring to the planet. The planet Earth should always be capitalized. If you are referring to soil, earth does not need to be capitalized.
"Earth" should be capitalized when it is being referred to as the proper noun for our planet, such as in "Planet Earth." However, when used in a more general sense to refer to soil or land, it is not capitalized.
When you are referring to the Earth's Moon then it is always capitalized, if you are talking about the moon of another planet then it is not always capitalized.
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.
Yes, "I am" is typically capitalized because "I" is a pronoun and should always be capitalized in English.
Yes, when referring to the title of the President of the United States, it should always be capitalized.
Yes. Days of the week are always capitalized.
Yes, it should always be capitalized.
No, circa does not need to be capitalized.
No, the word "rif" is not always capitalized. It should only be capitalized if it is part of a proper noun or at the beginning of a sentence.
Earth is capitalized when used as a planet such as Earth is the third planet in our solar system. If you are referring just to earth, as in soil, It is not capitalized. The sun warms the earth.