npm install @ngx-translate/core @ngx-translate/http-loader rxjs --save

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';

// import ngx-translate and the http loader
import {TranslateLoader, TranslateModule} from '@ngx-translate/core';
import {TranslateHttpLoader} from '@ngx-translate/http-loader';
import {HttpClient, HttpClientModule} from '@angular/common/http';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,

    // ngx-translate and the loader module
    HttpClientModule,
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useFactory: HttpLoaderFactory,
        deps: [HttpClient]
      }
    })
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

// required for AOT compilation
export function HttpLoaderFactory(http: HttpClient) {
  return new TranslateHttpLoader(http);
}

import {Component} from '@angular/core';
import {TranslateService} from '@ngx-translate/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})
export class AppComponent {
  constructor(private translate: TranslateService) {
    translate.setDefaultLang('en');
  }
}

{
 "demo.title": "Translation demo",
 "demo.text": "This is a simple demonstration app for ngx-translate"
}

<div>
  <!-- translation: translation pipe -->
  <h1>{{ 'demo.title' | translate }}</h1>

  <!-- translation: directive (key as attribute)-->
  <p [translate]="'demo.text'"></p>

  <!-- translation: directive (key as content of element) -->
  <p translate>demo.text</p>
</div>