You need to be Single or file as Married filing Separate and have a qualifying dependent. If you are married you need to live apart from your spouse for the last 6 months of the year.
Do you qualify for Head of Household?
https://ttlc.intuit.com/community/family/help/do-i-qualify-for-head-of-household/00/25539
Who is a qualifying person for Head of Household?
https://ttlc.intuit.com/community/family/help/what-is-a-qualifying-person-for-head-of-household/00/26624
You need to be Single or file as Married filing Separate and have a qualifying dependent. If you are married you need to live apart from your spouse for the last 6 months of the year.
Do you qualify for Head of Household?
https://ttlc.intuit.com/community/family/help/do-i-qualify-for-head-of-household/00/25539
Who is a qualifying person for Head of Household?
https://ttlc.intuit.com/community/family/help/what-is-a-qualifying-person-for-head-of-household/00/26624
you can also use this iRS website