He should stop his selfish behavior.

He studies in the library every day for self-improvement.

She emphasized the importance of self-determination.

He should stop his self-destructive behavior.

The robot initiated the self-destruction program.

He likes to take a walk in the park at dusk.

He dreams of becoming a champion in mixed martial arts.

As the proverb 'better safe than sorry' suggests, I recommend getting vaccinated.

He has a strong desire to be in the spotlight and always wants to be the center of attention.

She has an autoimmune disease.