Hi, I think this may be similar to my issue, I found out that to have the global $t injected like on previous version I neet to pass
globalInjection: true, in the createI18n() function options.

So your i18n.ts may look like this:

import { createI18n } from "vue-i18n";

const i18n = createI18n({
  legacy: false,
  locale: "ja",
  globalInjection: true,
  messages: {
    en: {
      message: {
        language: "English",
        greeting: "Hello !"
      }
    },
    ar: {
      message: {
        language: "العربية",
        greeting: "السلام عليكم"
      }
    },
    es: {
      message: {
        language: "Español",
        greeting: "Hola !"
      }
    }
  }
});
export default i18n;

@danielpetrica Wow it works like charm, thank you very very much

@boussadjra I'm glad it worked.
This may be useful in the future. I found out that $t is not available everywhere (like inside other .ts files) but if you add this function to the i18n file you can import it and use it to translate strings:

// file: i18n.ts
/**
 * it's ugly but we can use this to translate strings inside js code
 * @param key
 */
export const translate = (key: string) => {
    if (!key) {
        return '';
    }
    return i18n.global.t(key);
};

// another .ts file
import { translate } from 'path to i18n file'
...
console.log(translate('message.languge'))

How do I resolve the same issue in a js file?

@danielpetrica for me this.$t works inside component definition.

Vue3 and vue-i18n-next sample, it could works as bellow:

<template>
  <q-page class="flex flex-center">
    <img alt="Quasar logo" src="/imgs/logo.svg" />
    <div>{{ t("success") }}</div>
  </q-page>
</template>

<script>
import { defineComponent } from "vue";
import { useI18n } from "vue-i18n";

export default defineComponent({
  name: "PageIndex",
  setup() {
    const { t } = useI18n();
    return {
      t,
    };
  },
});
</script>

• import useI18n:

import { useI18n } from "vue-i18n";

• define function in setup():

const { t } = useI18n();

• using t in the template:

<div>{{ t("success") }}</div>

@hks2002 how to use t("") in <script></script>

if i only use in *.js file and not setup() how to use i18n? @hks2002

Hi ! I have same issue but with $tc. I pass globalInjection to true, $t is available but not $tc.

Hi ! I have same issue but with $tc. I pass globalInjection to true, $t is available but not $tc.

Hi @gwen1230 from what i can see the plurarization has been integrated in t()when using composition api https://vue-i18n.intlify.dev/guide/advanced/composition.html#pluralization

Hi ! I have same issue but with $tc. I pass globalInjection to true, $t is available but not $tc.

Hi @gwen1230 from what i can see the plurarization has been integrated in t()when using composition api https://vue-i18n.intlify.dev/guide/advanced/composition.html#pluralization

Yes I saw that and it works with composition API. But with global injection, $t is like the old $t, and $tc doesn't seem to exist.