1) "Full time" vs. "part time" doesn't matter for most purposes. While there are rules that take account of how many hours an employee works--for example, overtime--that tends to vary on a rule-by-rule basis; there is no global threshold for "full time" work from a legal point of view. That is, for example, a "part time" worker in CA who works more than 8 hours in one day gets overtime even though he or she is nominally "part time."2) Similarly, if you taking about eligibilility for benefits, to a great extent that is up to the employer to decide criteria--e.g. how many hours to qualify for vacation days, sick days, to be eligible to get health insurance (though there are some state rules on the subject, limiting employer discretion).3) To the extent it does matter, I believe your HR department is right--"full time" is usually 30 or more hours a week. However, this said, an employer is free to reduce a full time employee to part time at will, unless there is a contract to the contrary.4) No, it is not discrimination to call you "slow" unless you actually have a cognitive or mental disability; if you are, then it may be illegal harassment/discrimination against the disabled to use this term. However, there is no general rule or law saying that employers cannot insult their employees, as long as the insult, etc. is not on the basis of a specifically protected category, such as race, religion, age over 40, sex, or disability.Saying that a worker is too slow when that comment is not based on a protected characteristic is legal.