Conjugating "なる" and "する" with verbs - problems with translation

[Katjov]

Hi there
Could someone please tell me what the meanings of these conjuagtions of are. For example what's the difference between "海外に行くことになった" and "海外に行くことにした". Also, when do you use "こと" and when do you use "よう".

 

[Toritoribe]

Those expressions are all set phrases.

ことになる: the event is decided/arranged
ことにする: the subject decides to do so
Thus, the latter is the subject's will, but the former is not.

ようになる: to become~/come to~/
ようにする: to do something (so that~)/try to ~
The same goes to よう. ようにする is the speaker's volitional change, but ようになる is non-volitional.

 

[Katjov]

Thank you very much, that was very helpful