First of all -- we're talking about civil marriage, not religious marriage.
In the United States, some states require a couple to file as "husband" and "wife," so only opposite-sex couples can get married. In other states, the couple are simply "spouse" and "spouse", and same-sex marriage is allowed. Civil marriages among 3 or more people are not legal anywhere in the U.S.
I'm not sure people realize that when a person surgically corrects his or her sex, that change is also reflected on their identification (driver's license, passport, etc.). Therefore, when a person who was born a man becomes a woman, legally speaking, she is then free to marry a man, even in states where same-sex marriage is prohibited.
As far as the rest of t he world is concerned I really do not know. In Mexico City, same sex marriages are allowed, and people who are transsexuals can marry either people of their new sex, or different sex, since their identity, is changed, and all their documents need to be changed according to their new sexual identity.
In some countries, polygamous marriages are traditional and common, so they are legal. I believe Nepal is one such country. I've heard that it is traditional for two brothers to marry the same woman.
Any state that allows you to change the sex on your birth certificate OR allows same sex marriage (the last is arguable but works.)
In some states, yes the state recognizes the sex change as legal and thereby marriage of a genetic/birth man to a Male to Female transexual as legal. Others do not and without same sex marriage a man may not marry a Male to Female transexual.
For the most part, yes. They can certainly marry before surgery. After surgery, they can marry someone opposite their transitioned sex in a great deal of the world, though not in every state in the US. Transsexual women are more likely to be able to marry where gay marriage is not legal. It seems as LGBT people get rights, actual transsexual persons who are not transgendered nor a part of the LGBT lose theirs. To take a TS woman's mainstream rights and then force her to settle for a cheaper version as LGBT rights is neither ethical nor fair.
It is legal to marry a second cousin in California. It is not legal to marry anyone else in your family. California also allows first cousin marriage.
Yes. A lesbian can marry a man anywhere. A lesbian can marry a woman in any of the states and countries that have legalized same-sex marriage.
Yes and no it depends on the state. Most states will allow a post-op transsexual marry a person of the opposite sex of their new gender and will still honor a marriage previous to gender reassignment surgery.
Um......marry your company? Well....I guess...you could.....if you wanted.
No. Marriage is a legal status. You need to obtain a divorce to marry again.
In US law a common law marriage does have some legal standing; but is not considered a legal marriage. In most cases a legal marriage anywhere in the world is considered legal in the United States. Therefore if Mexico considers you to be married then the US does too.
Because it is not written anywhere that you MUST get married at any age or due to any circumstances. You don't have to marry for sex, you don't have to marry for children, you don't have to marry to live together. If you don't want to get married, then don't. It isn't a legal obligation to marry.
Child marriage is prohibited in Sikhism. After getting to legal age of marriage he/she can marry
If you live in a place where same-sex marriage is legal you will be able to marry at the age of 18. To marry at a younger age requires parental consent and possibly judicial consent. If same-sex marriage is not legal where you live, you can travel to someplace where it is and marry there.