Fixing my grammar on a line in my essay

Question

I'm revising an essay that I wrote and one of my lines is a little beyond my current grammar abilities. My original line is:

友達はそこに行ったことは分かったことはありません

What I'm trying to say is:

My friend still has not discovered that we went there.

Since I'm not sure how to rework the multiple experiences to make sense, my first thought is to change it to something like:

友達はそこに行ったこと(?)まだ分かりません

To potentially be read more like "My friend does not yet know that we went there". Though I'm not sure on the proper particle to use there or if that version makes any more sense than the previous.

Any suggestions for how I can best phrase this?

Answer 1

Your last attempt is close.

• 分かる is "to understand" rather than "to notice". Try using 気づく instead. And the particle you need before 気づく is に (although を is sometimes acceptable).
• は should be replaced with が in subordinate clauses. This is because subordinate clauses does not work as the topic of the whole sentence.

Now you'll get this:

友達は（私が）そこに行ったことにまだ気づいていません。

As for why I used 気づいていません instead of 気づきません, see: When is Vている the continuation of action and when is it the continuation of state?

私が can be omitted if it's inferred from the context. But you have to use 私が instead of 私は here, because the topic of the whole sentence is not 私 but 友達.

EDIT: ことがある is closer to "there are times when ～". Saying "友達は（私が）そこに行ったことにまだ気づいたことがありません" would sound like you go to the place on a regular basis but your friend has never noticed that even once.

Answer 2

When you use「に」、it refers the matter as the target.

E.g

私は　友達に　プレゼントをあげました。 I gave a present to my friend.

The usage of「に」here is the same as above used as the target.

You can find good materials here. http://www.mlcjapanese.co.jp/Download/Particles.pdf