How to use  ----そう & ----ところ

It's almost Valentine's!!

仕事が始まりそうです。

しごとがはじまりそうです。

My work is about to begin.

電車が来そうです。

でんしゃがきそうです。

The train is about to come.

彼らは結婚しそうです。　　　
する conjugates to し when followed by そう

かれらはけっこんしそうです。　　　

They are on the verge of getting married/They seem likely to get married

ーーそう　has meanings of " about to " " on the threshhold of " " on the verge of "about a certain action. Notice that it's not confirmed yet, it's just in the process of confirming a certain action. Which means that there is a small amount of doubt or gap that exists. [Most likely to] would probably be another close meaning. 

**Keep in mind that this is not a direct translation, but more of a translation that can be understood in English. 

彼女はデパートに行くところです。

かのじょはでぱーとにいくところです。

She is about to go to the department store.

今、帰るところです。

いま、かえるところです。

I'm about to go home now.

Let's get on the train. 

電車に乗るところです。

でんしゃにのるところです。

I'm about to hop on the train. 

ーーところ　also contains meanings of " about to " " on the verge of " " on the threshold of " about a certain action. The big difference is that it's confirmed; there are no doubts left. The action might not have happened yet, but the certainty of an action occurring is confirmed unlike ーーそう.  

Certainty-wise, ーーそう is 70-80% sure, while ーーところ is 91-99.9999% sure 

The best thing to do is to listen for ーーそう、ーーところ and decipher the types of situations they are used in and what kind of distinction is emphasized.