March 4 = March forth
Valentine's Day is the subject of that sentence.
Mrs. Marcus is the complete subject of the sentence.
Yes, it is.
No. There is no verb.
Valentine's Day is the subject of that sentence.
Yes, that's a complete sentence. Maybe somebody you really want to hear from will call tomorrow.
It is only capitalized if it is part of a name (Eg, Larry's Day Care) or at the start of the sentence; in this case you only capitalize 'day' and not 'care'.
The superlative form is used: This is the hottest day of the year.
Today is the coldest day of the year.
Venus has a day that is longer than its year. Venus takes about 243 Earth days to complete one rotation on its axis (day), but it only takes about 225 Earth days to orbit the sun (year).
This is a fragment. To make it a sentence you could write " When Lola prepares for a day at the beach, she packs a big lunch."
It, because is is a verb