They yell for no reason.
Everyone gets mad at their spouse from time to time. It just happens. But if you find that your partner yells at you often and for seemingly no reason, yeah, this is a type of abuse.
They call you names.
Name calling is a type of abuse. No one should ever call you names, be it “bitch” or “asshole” or anything like that. It’s a type of bullying that is completely unacceptable.
They try to make your plans for you.
Even if they don’t yell or call you a name, when your partner starts making plans for you, like where you’re vacationing or who you can or can’t hang out with, it is a type of abuse. Control is abuse.
They control your money.
This type of controlling, as with your schedule, is abuse. If they’re constantly concerned about your money or giving you only a modest amount of money to live on (say if you’re a homemaker) this is a type of abuse as well.
They manipulate and intimidate.
Manipulation and intimidation often don’t require any kind of yelling or name calling or controlling, but they use your thoughts and emotions and turn them against you. They know your weaknesses and cleverly exploit them.
They strike you, sexually assault you, or verbally torment you.

Under no circumstance is it not abuse if your partner hits you. If you say no to sex and they force themselves on you, that’s also abuse. Always. If they verbally assault you, it’s abuse. Seek help if you’re in this kind of situation.