Yes, thats the sort of thing, although in my case:
'The galloping horse came to a sudden stop and I fell off.'
Here are some examples from my grammer book. Perhaps typing them in will help me remember them
うたう こと が すき です。I like to sing.
しゃちょうさん が いった こと を おぼえて います か。Do you remember what the company president said.
こどもたち も いきたかった こと を わすれました。I forgot [the fact] that the children also wanted to go.
There are some more examples specifically for 'koto ga aru' which means 'ever do/occasionally do':
ときどき おすし を たべる こと が あります。I eat sushi from time to time
まいとし なんどか りょこう を する こと が あります。 Several times each year I do some travelling.
There are also some examples for 'koto ga dekiru' which means 'be able to do/can do':
おにいさん は ぎたあ を ひく こと が できます。 Older brother can play the guitar.
め が いたくて、みる こと が できません でした。My eyes hurt, and so I wasn't able to see.
There's also 'koto ni naru'/'you ni naru' which is 'come about/come to pass/wind up doing/turn out that'.:
どようび に も はたらく こと に なりました。It turns out that I will be working on Saturday also.
おかあさん が びょうき で、 びょういん に いく よう に なりました。 Mother was sick, so I wound up going to the hospital.
And there's 'koto ni suru'/'you ni suru', which is 'decide to'
あした とうきょう に いく こと に しました。I decided to go to Tokyo tomorrow.
やはり しゃちょう と はなす よう に しました。He decided to speak with the company president after all.
The above examples all used the dictionary form, but there are also some 'koto ga aru' examples for the informal past form (-ta form). These mean 'have ever done/have had the experience of doing':
ようろっぱ に いった こと が あります か。Have you ever been (gone) to Europe?
さしみ を たべた こと が ありません。I have never eaten raw fish.
So, after all that, lets try that horsey example:
'The galloping horse came to a sudden stop and I fell off
Horse = uma; to gallop = hashiru; tomaru = to stop (intransitive); suddenly = fui ni;fall=ochiru
uma wa hashiru koto ga fui ni tomarimashita. soshite watashi ga ochimashita.
午は走ることが不意に止まりました。そして私は落ちました。
Maybe use 'sorede' rather than 'soshite' perhaps. or maybe 'suru to'
I wonder if that's anywhere near right
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