No....you cannot file Single for your 2019 taxes unless you get divorced before the end of the year.
Your W-4 setting only sets your withholding level, it doesn't commit you to file the same status on your year-end tax return.
But for your 2019 tax filing, if you are still married at the end of the year, then you must file either Married Filing Joint (MFJ) with your spouse, or Married Filing Separate (MFS).
MFJ is almost always easiest and most advantageous, even if one spouse had no income, while filing MFS requires two separate tax returns, and some credits/deductions are eliminated.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
