Arguments. The conversations that contain yelling, screaming, insults, hurting, frustration, and occasionally...humor.

If you are uncertain how to write one, I have a few tips for you.

A Reason:

Perhaps the frustration has been building in one of your characters for days, weeks, and in extreme cases, years. When the emotions build up so does the level of the argument. 

Emotions that has been strengthening for hours compared to minutes will blow up in a more dramatic way.

So there are many reasoning for the argument. Maybe what the discussion is about isn’t actually what the person is upset about. Two characters may be fighting over who ate the last muffin but in reality one of the characters have been feeling left out and has taken their frustration on a muffin.

Maybe the characters simply hate each other and look for any reason to get under the others skin. There are so many reasons and its all determined on your characters.

Serious vs Trivial:

The serious arguments compared to trivial disagreements have much more emotion behind it. There has to be pain, mixed with other emotions creating a complicated mess. 

Most quarrels are minor, (usually not unimportant), but not consequential. Serious arguments can include physical fighting, hateful words, and revealing feelings they have never shared before. But not all significant disagreements are relationship ruining. In fact it can strengthen the bond. 

Trivial- Develops the situation

Serious- Develops the characters

(Note: This isn’t correct all the time. Serious can develop the situation as well as trivial developing the characters)

Development:

I just touched on it but most if not all arguments should be impactful in some way. Minor or Major. 

Maybe it should foreshadow something that's going to happen or dawns realization on a character. It can destroy or build relationships, or bring the problems up. They can also show the contrasts between characters.