そのシャツ、正直しょうじきちょっとダサいと思おもう。

sono shatsu, shoujiki chotto dasai to omou.

Honestly, I think that shirt is a bit uncool. casual

この髪型かみがたは今いまの若者わかものにはダサいです。

kono kamigata wa ima no wakamono ni wa dasai desu.

This hairstyle is uncool to young people today. neutral