"What" is often used to signal a question.
An example would be, "What is the remainder when you divide 7 by 3?"
You can start a sentence with "Also"
No, You cannot use but to start a sentence.
Yep. There's no problem with using 'an' anywhere you want to. You shouldn't use and at the start of a sentence, though.
I usually respond based on the context of the conversation.
Well that is a tricky question but i would say at the start of a sentence people would often use "I" at a start of sentence. There is loads of words to start a sentence so i can't tell you all of them obviously. example: "I" went to the shops to buy sweets.
no
That cannot be done.
A capital letter.
the rain doesn't start until the night.
I would like to start with a startling revelation.
Yes, it is generally acceptable to start a sentence with "but," particularly in informal writing. However, it is best to use this approach sparingly and ensure that the sentence structure is clear and the use of "but" is appropriate for the context.
yes specially if the sentence is an interrogative sentence. for example "From where does this package came from".