Angular2 - route with language

Hello i would like to create routes with language in this format:

www.domain.com/lang/sometimes

Example:

www.domain.com/en/sometimes
www.domain.com/de/sometimes

Is it possible write to route something like:

RouterModule.forChild({
   path: ':lang/sometimes', component: TestComponent
})

Is it possible? How to set to url default language? For example when app starting, set dynamically lang parameter to url.

Thank you for your advices