No, it's not. It has no subject or verb. Therefore, it is only a phrase.
Using the word "then" at the beginning of a sentence is not incorrect. However, it does not make a sentence complete. A complete sentence must have, at a minimum, a subject and a verb. "Then" is neither of those.
Sure, just provide me with the beginning of the sentence and I can help complete it for you.
No it does not. An example of a complete subject NOT in the beginning of a sentence could be: "In the morning, the black dog begged for his breakfast." Another: In the corner of the cage looking hungry ready to pounce crouched the wild tiger.
Yes, "Is you won the trophy" is a fragment sentence because it is missing a subject and does not express a complete thought. It could be corrected by adding the subject "You" at the beginning to make it a complete sentence, such as "You won the trophy."
because other wise it would look dumb
Leave it as is ? It's a complete sentence.
No. A sentence must contain a subject and a verb. "Here's why" does not have a subject or a verb.
if you mean from the beginning of a sentence yes then you would have to anyway because its at the beginning of the sentence anyway.always capitalize the first word of a quotation if needed.
A sentence beginning with laugh is an order.
An introductory phrase or clause is a group of words at the beginning of a sentence that provides context or sets the stage for the main part of the sentence. It is not a complete sentence on its own and is usually followed by a comma.
You should generally follow any punctuation that is in the original sentence including capitalization. If you are quoting in the middle of a sentence, however, then the beginning of the quote is generally only capitalized if it begins with a proper noun.
whole crop harvested in one week