Ули, вы действительно не знали, как перевести? или хотели подтвердить свои соображения?

Понятно, это для нас задание! )

Elena: chum up TO him. Thanks for your answer - that was very creative and idiomatic!

Vladislav: я просто не был уверен в том, что "замышлать" означает. Теперь знаю)

Uly, welcome ! Our dictionaries say it's "with" :(
http://wooordhunt.ru/word/chum%20up

Uly, is it also good to use "cooking up" instead of "hatching up"?

Also "to concieve"?

Yes, you can say COOKING UP, HATCHING UP, or UP TO in the sense of planning something - usually underhanded. However CONCEIVE (the rule is: i before e except after c) doesn't really work in this meaning.

CHUM UP WITH is more like forming an alliance with like-minded people, whereas CHUM UP TO is to seek out someone's friendship with ulterior motives.

Thanks)

Ули, вы кладезь знаний для нас.

Спасибо, Владислав! С большим удовольствием. Я обожаю помогать людям с английским) Кстати, давай на ты -- ты же рискуешь заставлять меня чувствовать себя старым)))

Thanks, Uly. You really are what I said. By the way, what's the right way to pronounce your name? ['u:li:], ['ju:li:], or maybe even [ju'lai]? So that I can right your name correctly in Russian.

In English it's a "fount of knowledge" and thank you for the compliment. My name is pronounced у́ли)

Спасибо, Ули.