Can I claim 50% of the asset even if my spouse inherited in from his parents

Q. I have been married together for 20 years. 
My wife owns two apartment with value 1million USD respectively, and 300,000USD in cash. 
I would like to find ways to secure some share of asset under your name. 
A. If you remain married, and she refuses to buy property under your name(or co-own it), there is nothing you can do about it. There is no such law as to enforce one party to have the ownership of the property. The law will not intervene. 
If you decide to get divorced, then there are many ways you can secure your contribution. If you have been married for 20 years, the court will rule 50% of the total asset anyway. 
As for "the lawyer here in Changwon said that if she just puts 50% of the apartment in my name, she can fairly easily get that back in a future divorce- since she can prove it was given to her by her father" this advice is half wrong and half right. 
It all depends on WHEN she got that property from her father. The court does still recognise the contribution of you, that contribution is that you contributed in "retaining and maintaining the states of the asset" . So if that property was given like 10 years ago, you can still claim 40-50%. 
If you decide to get divorced or thinking about divorce and wish to secure the share of the asset, the first step is to have the court to temporarily seize the asset( so she cannot sell till the court grant her own share)