Not with wife for over a year do I file single or married

[kholford94]

Filing separate for second year

[VolvoGirl]

If you didn't get divorced yet you still file as married.  Either a Joint return together or Married filing Separate or Head of Household if you have a qualifying dependent.

[DoninGA]

If you are still legally married then you have to file either as Married Filing Jointly or Married Filing Separately.

However, if you have not lived with your spouse at any time during the last six months of the year and you have a qualifying child as a dependent you may be eligible to file as Head of Household - https://ttlc.intuit.com/community/married/help/can-a-married-person-claim-head-of-household-filing-s...