No; ‘came’ is the simple past tense conjugation of the verb ‘to come,’ meaning that you need to be speaking in the past tense, sans auxiliary verb (to have) to use it. “You came back?” Is the correct way to say that, though it can also be in the indicative mood.

Come back sentence example

1. I can come back .
2. I know she wanted him to come back .
3. Well, do you want me to come back home?
4. Soon she would need to come back home to get ready for college.
5. I told Julia and Rachel that I’d come back if I didn’t find you here.

1. Commas (Eight Basic Uses)
2. USE A COMMA TO SEPARATE INDEPENDENT CLAUSES.
3. USE A COMMA AFTER AN INTRODUCTORY CLAUSE OR PHRASE.
4. USE A COMMA BETWEEN ALL ITEMS IN A SERIES.
5. USE COMMAS TO SET OFF NONRESTRICTIVE CLAUSES.
6. USE A COMMA TO SET OFF APPOSITIVES.
7. USE A COMMA TO INDICATE DIRECT ADDRESS.

Yes, there should be a comma after the greeting and before the name. Happy Birthday is a greeting. You are saying this to someone. Since you are directly addressing someone in a sentence, set off the address from the name with a comma.

To name the traditional song, both words are capitalized: “Happy Birthday to You,” or “Happy Birthday.” In dialogue (as in a published novel or story), the first term would normally be capitalized at the beginning of a sentence: “Happy birthday, Rhoda!” But in a personal greeting, you can style it however you wish: …

If you are telling someone “thank you” directly, you always need a comma after “thank you.” This is the most common way of using the phrase, so in most cases you will want that comma. You should also put a comma or a period after “thank you” if it’s the last part of a letter or email before your name or signature.

Other Ways to Say Happy Birthday

1. All the best on your special day!
2. Have a great birthday!
3. I wish you a happier birthday than anyone else has wished you!
4. It’s time to celebrate!
5. Many more happy returns!
6. May you have a fantastic day and many more to come!
7. May your birthday be filled with laughter!

As Janus Bahs Jacquet says in his comment, “Happy Birthday!” is not a sentence according to the normally accepted definition. But that does not make it unacceptable (as is usually quite obvious when it is used).

To Parents

1. “Happy birthday! I’m your karma!”
2. “Happy birthday! Your gift is me admitting you were always right!”
3. “Happy birthday, mom/dad! I was a gift to you, it’s called ‘my’ birthday!”
4. “Happy birthday! The only thing getting old is that phrase!”
5. “Happy belated birthday, sorry I was (insert age here) years late!”

Quarantine happy birthday wishes.

1. Since I can’t see you on your birthday this year, I’m sending you this virtual gift.
2. Happy birthday.
3. Holy crap.
4. Sending you a virus-free birthday hug on your special day.
5. Happy birthday with toilet paper cakes.
6. Happy birthday.
7. Nothing can rain on your parade.
8. Happy birthday.

Fun lockdown birthday messages: “Thank God we are on lockdown or I would have to actually see you!” “This birthday card is packed full of virus-free hugs and kisses!” “Don’t worry that your birthday is during lockdown, we can make up for it with a BIG party when we’re finally reunited.”