take someone/something seriously
US /teɪk ˈsʌmwʌn/ˈsʌmθɪŋ ˈsɪriəsli/
UK /teɪk ˈsʌmwʌn/ˈsʌmθɪŋ ˈsɪriəsli/

1.
to believe that someone or something is important and deserves attention
:
•
You need to take your studies seriously if you want to succeed.
•
Don't take his threats seriously; he's just trying to scare you.