From all the time I've used Hangouts which is a while I can only tell you paragraphs within one message isn't possible (or obvious as I've never managed it)

Assuming texting works the same as the message function anyway, I use 8sms for texts.

 

I was wondering too.
It's there when writing e-mails, but not for SMS ???

 

8sms doesn't have it either. Neither does Messenger (Facebook). As hinted at above, if the text entry field does not allow paragraphs, you won't get an enter key. You'll get an onscreen send arrow instead.

 

Aha, I'm on the Swiftkey beta, holding just brings up emoji and tapping just sends.

 

there is no other way to this, especially if you dont want to keep using samsung keyboard

just one solution...
this

in hangouts

in keyboards

press and hold "mike" button

go to settings... with the gear symbol

go to " my hot keys"

turn it on

choose any number from 1 to 0 (in this case i choose 0)

press enter key

... thats it back space and go out of the settings

now go to hangouts an d type something
to go to next line , press and hold key 0

BINGO... u have an enter key

cheers

 

If you're using the google keyboard app, you can access the enter key by changing the emoji button using shift to get to capitals. It should then allow you to use an enter key. Please note that this does not work with the automatic capitalization; you need to shift yourself.

EDIT: Ah, it seems OP already discovered that.

EDIT EDIT: corrected a typo

 

I've just tried that on mine and I don't need to hold the emoji button, just press 'shift' and the emoji key becomes a return/enter key.