そう

雨天中止になりそうな計画だな。

That's a plan that sounds likely to be cancelled by rain.

今週は、訳あって、憂鬱な一週間になりそうだ。

For some reason it looks to be turning out to be a depressing week.

そう言えば、肝心要の部分を何も決めていなかった。

Now that you mention it, I wasn't involved in the decision-making for the vital part.

失敗してあれほど悲しそうな顔(かお)をする奴(やつ)が、いるかな？

Is there really any guy who has such a sad face when they mess up?

「これはとてもおもしろそうだね」とひろしが言います。

"This looks pretty interesting," Hiroshi says.