View full size image. How long a healthy pregnancy lasts can vary by as much as five weeks, even when doctors precisely determined the date of conception, a new study suggests.
Exemptions for dependents. You can usually claim an exemption for each of your dependents. A dependent is either your child or a relative who meets a set of tests. You can't claim your spouse as a dependent. You must list the Social Security number of each dependent you claim on your tax return.
If someone else can claim you (or your spouse, if filing jointly) as a dependent, whether or not they actually claim you, then you are not allowed to claim any dependents of your own (nor can you take any tax exemptions, even for yourself).