Can't bind to 'typeahead' since it isn't a known property of 'input'

You should probably import the TypeaheadModule into your NgModule definition of your app:

import {TypeaheadModule} from 'ng2-bootstrap/components/typeahead';

@NgModule({
    imports : [
        //...
        TypeaheadModule
    ],
    //...
})
export class AppModule {}

Import the TypeaheadModule from ngx-bootstap and make sure to install the module in npm using:

npm i ngx-typeahead

 import { TypeaheadModule } from 'ngx-bootstrap/typeahead';
// or
import { TypeaheadModule } from 'ngx-bootstrap';

@NgModule({
  imports: [TypeaheadModule.forRoot(),...]
})
export class AppModule(){}