Here's a breakdown of the phrase:
* तुम (Tum) - You
* कभी (Kabhi) - Ever, never
* अलविदा (Alvida) - Goodbye
* नहीं (Nahin) - Not
* कहते (Kahte) - Say (plural, informal)
This phrase is a direct translation and grammatically correct, but it might sound a little formal or stiff. You can make it more casual and natural depending on the context.
Here are some alternative ways to say "you never say goodbye" in Hindi:
* तुम कभी विदा नहीं लेते (Tum kabhi vida nahin lete) - You never take leave.
* तुम कभी जाते ही नहीं (Tum kabhi jaate hi nahin) - You never leave.
* तुम कभी विदाई नहीं करते (Tum kabhi vidaai nahin karte) - You never say farewell.
The best option will depend on the specific situation and who you are talking to.