Shows your comment is based on personal feelings rather than facts.

Subjectivity

Can be used to imply something is obvious and should be noticed without asking.

Hint of Sarcasm

Polite way to introduce your disagreement or different opinion on a matter.

Use to assert your opinion when you feel strongly about it.

Prepares listener for a criticism or negative opinion to follow.

Can convey annoyance or frustration in the context it's used.