On top of old Smokey, all covered with snow.
No, You cannot use but to start a sentence.
You can just about use any word possible 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.
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.
Anyway.
No, because it is never good to start a sentence with the word "but".
Yes.
You are too late to start this job.
for the word summer you use its capital s if in a title or start of sentence
can you start a sentence using the word phishing?
You can use however instead.
That depends on what your definition of "is" is....