Writing Reader here wondering about something, how do you writers make it clear who's talking without telling it explicitly who is the one talking?

[J_Chemist]

Using descriptions helps.
Words, too.

 

[lnv]

Well, let's I have been reading a lot of LN in the past where I was confused about which one is talking especially in the group unless they have a very obvious distinct way of talking or something like "Character a said", so my question would how you guys would write dialogue and make it clear which character is talking especially if in a group?

I am in the he/she said camp, just add action flavor to it so it doesn't look annoying/stale

Adding quirks sounds nice in theory, but it is a bad idea. It may be okay if you have a published book, but in web novels where people read once or twice per week and read dozens of novels, expecting readers to remember all the quirks is only going to harm enjoyment for many readers, especially when more than 2 people are talking

 

[Jemini]

What does ending words in this context mean here and how would they be used?

It's a strictly Japanese thing. It's a word that gets tacked onto the end of the sentence.

Desu is the most common one, since it actually has a legitimate meaning in the language. "That is."
There are also the the desu derivatives, like dayo-ne (that is, huh?), or "so dayo" (that really is) or combining them into "so dayo-ne?"
I've also heard some strange ones like nano-pa, and Gosarimasu, which also have meanings, but don't necessarily fit well with most sentences.

The Japanese trend is to say who's the speaker by assigning an ending word to a character, have that character just about always use that ending word, and have that character be the only one to ever use that ending word.

Some Japanese writers take it to the extreme of having such strange ending words I swear they're just making up words.

EDIT: There are also a few ending words that tell you a little about the position of the person talking. For instance, "degozaru" and "dearimasu." They are actually the respective male and female speech versions of the desu-derivative ending phrase that's considered appropriate for a high-class servant, although "degozaru" can also be used by samurai in addition to butlers. However, "dearimasu" would only be used by maids.

(Oh, yes, and that's one other interesting thing about Japanese. It's a speaker-based gendered language. As in, you use some words differently depending upon whether you as the speaker are male or female. This is different from a subject-based gendered language like Spanish where you might say the same word differently depending on whether you are talking about a male or a female subject.)