Do i put single with no kids on my taxes?

The children would not be entered on your return at all unless you claimed a benefit for them. For your fiance to claim them, the children would have to pass the qualifying child or relative tests.

To be a taxpayer’s qualifying child, a person must satisfy four tests:

Relationship — the taxpayer’s child or stepchild (whether by blood or adoption), foster child, sibling or step-sibling, or a descendant of one of these.

Residence — has the same principal residence as the taxpayer for more than half the tax year. Exceptions apply, in certain cases, for children of divorced or separated parents, kidnapped children, temporary absences, and for children who were born or died during the year.

Age — must be under the age of 19 at the end of the tax year, or under the age of 24 if a full-time student for at least five months of the year, or be permanently and totally disabled at any time during the year.

Support — did not provide more than one-half of his/her own support for the year.

Qualifying Relative

• Do they live with you? Your relative must live at your residence all year or be on the list of “relatives who do not live with you” in Publication 501. About 30 types of relatives are on this list.
• Do they make less than $4,050? Your relative cannot have a gross income of more than $4,050 and be claimed by you as a dependent. 
• Do you financially support them? You must provide more than half of your relative’s total support each year.