When to use ください (kudasai) or お願いします (onegaishimasu) in requests?


When asking for something I seem to hear sentences end in both ください (kudasai)
and お願いします (onegaishimasu). Is there a difference and how do I know when to
use which?




[Here](http://japanese.about.com/library/blqow15.htm) there's a nice
explanation, but I'll quote it here for easy reference, with some additional
info:

ください and お願いします are both used when making a request.

  * ください (kudasai) is used:

>   1. After the particle "o" を, for example when ordering food: "水をください" (
> _Mizu o kudasai - Please, water._ );
>   2. When asking something that involves an action, along with the verb in
> the `-te` form, like: "ちょっと待ってください" ( _Chotto matte kudasai - Please, wait._
> ). **Note** : do not use _onegaishimasu_ here.
>

  * お願いします (onegaishimasu) is used:

>   1. Also when ordering food, but in this case "を" is not necessary. Just
> say: "水お願いします" ( _Mizu onegaishimasu_ ); **Note** : Onegaishimasu is more
> polite/formal than kudasai.
>   2. When calling for someone's attention; for example, a waiter/waitress to
> your table.
>   3. Use onegaishimasu when requesting a service that you cannot fulfill
> yourself: "東京駅までお願いします。" ( _Tokyo eki made onegaishimasu. - Tokyo Station,
> please_ [to the taxi driver]) **Note** : do not use kudasai here.
>   4. Use onegaishimasu when asking for someone over the phone: 和子さんお願いします (
> _Kazuko-san onegaishimasu. - May I speak to Kazuko?_ ) **Note** : do not use
> kudasai here.
>




[Here](http://japanese.about.com/library/blqow15.htm) there's a nice
explanation, but I'll quote it here for easy reference, with some additional
info:

ください and お願いします are both used when making a request.

  * ください (kudasai) is used:

>   1. After the particle "o" を, for example when ordering food: "水をください" (
> _Mizu o kudasai - Please, water._ );
>   2. When asking something that involves an action, along with the verb in
> the `-te` form, like: "ちょっと待ってください" ( _Chotto matte kudasai - Please, wait._
> ). **Note** : do not use _onegaishimasu_ here.
>

  * お願いします (onegaishimasu) is used:

>   1. Also when ordering food, but in this case "を" is not necessary. Just
> say: "水お願いします" ( _Mizu onegaishimasu_ ); **Note** : Onegaishimasu is more
> polite/formal than kudasai.
>   2. When calling for someone's attention; for example, a waiter/waitress to
> your table.
>   3. Use onegaishimasu when requesting a service that you cannot fulfill
> yourself: "東京駅までお願いします。" ( _Tokyo eki made onegaishimasu. - Tokyo Station,
> please_ [to the taxi driver]) **Note** : do not use kudasai here.
>   4. Use onegaishimasu when asking for someone over the phone: 和子さんお願いします (
> _Kazuko-san onegaishimasu. - May I speak to Kazuko?_ ) **Note** : do not use
> kudasai here.
>

