Khushi bandhu.
"Friends" in Bengali is বন্ধু (bandhu).
Happy in Bengali is pronounced as "খুশি" (khushi).
Subho Bibaho Barshiki
I'll use it as a sentence. "THATHAREE!" Dora cried to Lola in Bengali. Happy?
sukhi bibahito jibon
Subho Bibaho Barshiki !!!!
You say "Happy new year!", or just in shorter versions, "You too"
Bhalobasa jug jug jio sudra
সুখী নতুন বছর sukhī natuna bachara
In Bengali, you can say "না" to say no.
In Bengali, "Happy Father's Day" is said as "শুভ পিতার দিবস" (Shubho Pitar Dibosh). You can also use the phrase "বাবাকে শুভ দিবস" (Babake Shubho Dibosh), which means "Wishing a happy day to Dad."
In Bengali we will say 'srimoti'.