do they have partners who are 'unwed' living together?
Yes - Living as unwed partners is also known as cohabitation.
Family structure in the United States
Living as unwed partners is also known as cohabitation. The number of heterosexual unmarried couples in the United States has increased tenfold, from about 400,000 in 1960 to more than five million in 2005. This number would increase by at least another 594,000 if same-sex partners were included. Of all unmarried couples, about 1 in 9 (11.1% of all unmarried-partner households) are homosexual.

The cohabitation lifestyle is becoming more popular in today's generation. It is more convenient for couples not to get married because it can be cheaper and simpler. As divorce rates rise in society, the desire to get married is less attractive for couples uncertain of their long-term plans.
most common type of family in the us Single-parent homes in America are increasingly common. what are the different types of family structures in the united states? The traditional family structure and alternative family forms what is meant by a 'nuclear family'? The nuclear family consists of a mother, father, and the children in which scenarios would one have 'stepfamilies'? A step family is a family where at least one parent has children that are not biologically or adoptive related to the other spouse or partner. Either parent, or all, may have children from previous relationships. who would be considered as an 'extended family'? An extended family is a family that extends beyond the nuclear family, consisting of parents like father, mother, and their children, aunts, uncles, grandparents, and cousins, all living in the same household.
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Family structure in the United States [SEP] Unwed partners
Living as unwed partners is also known as cohabitation. The number of heterosexual unmarried couples in the United States has increased tenfold, from about 400,000 in 1960 to more than five million in 2005. This number would increase by at least another 594,000 if same-sex partners were included. Of all unmarried couples, about 1 in 9 (11.1% of all unmarried-partner households) are homosexual. The cohabitation lifestyle is becoming more popular in today's generation. It is more convenient for couples not to get married because it can be cheaper and simpler. As divorce rates rise in society, the desire to get married is less attractive for couples uncertain of their long-term plans.