Yes, they are valid your entire life. Keep it safe because you will need it off and on to prove your age for various reasons. You need it to get a passport and for many other things.
Yes. In the United States, you do not need to show a birth certificate to get married. What you need to show is valid photo ID. Foreigners usually show their passports.
birth certificate
Yes, typically you need a valid form of identification to sign a birth certificate.
He has provided a real birth certificate, authenticated as valid by the Hi Department of Health.
No, a birth certificate alone is not sufficient for entry into the US. You will need a valid passport or other approved travel document.
Yes, as long it have your correct information on it.
6 months ... I guess
No, a baby cannot travel to Canada with only a birth certificate. They would need a valid passport to enter the country.
They will receive a new birth certificate with the new parent's name in the place of the old. The new certificate becomes the legal one and the old certificate is not valid.
No passport required
If it doesn't have an expiration date and the store still honors it, then yes, it is valid.
In some states if a person requests a change to their birth certificate such as a change of gender or change of name the actual birth certificate is updated as if it was always that way. In other states an affiliate of correction is issued. It usually consist of a copy of the original birth certificate with a certified statement showing the correction and stating that this is a valid birth certificate for the stated person.