Good question, I have been wondering myself.
Until recently, yes, it was frowned upon, but in recent text it has become more acceptable;
much like the use of beginning a sentence with 'but'.
I hope that answered your question.
No, it's not improper.
Therefore, because it is not improper, one may begin a sentence with "therefore."
No, it's not improper.
this is not an improper sentence.
It was quite improper for you to ask such a question.
Starting a sentence with "for" is not necessarily improper, but it may make the sentence sound more formal or structured. It can be used to introduce a reason or explanation in the sentence. However, overusing it may affect the flow of the writing.
The subject is improper for this forum. I got a citation for my improper left turn into oncoming traffic.
She received a warning for her improper conduct during the meeting.
Here are 3 examples:The book is improper for him.This movie is improper for the children.Why did you let her see this improper show?
The word 'is' can begin a sentence but not be a question when it is the subject of the question. Example sentence - Is can be the subject in a sentence. But only in sentences of that type (above) or, 'Is' is a two letter word. Otherwise is cannot begin a sentence.
Yes. There is no word that cannot begin an English sentence.
It is possible to have a sentence with the word it at the beginning, as this sentence proves.