1. Live together for a while.
There is a word in Japanese called "Narita Break Up", which originated from an airport in Japan called "Narita Airport". Many couples or newlyweds come back from their honeymoon. After this period of time, they felt that this person was not suitable to spend the rest of their lives with themselves, so they broke up at the airport. Living together for a period of time, you see the ugliest side of this person. No matter how glamorous a person is outside, returning home is the truest side after he takes off his disguise. If you still firmly believe that you want to spend your life with this person, then you can get married.
Check the details
See how he treats his parents. Every time I call home, do I listen to my mother patiently and answer with a smile, or hang up impatiently?
See if he is equally polite to people close to him. See if he will thank you for your efforts and apologize for your mistakes, instead of taking everything for granted.
See if he will take it out on you or deal with his emotions rationally when he encounters unhappy things.
These small details can show the quality of this person. If he is of good quality, he is certainly suitable for marriage!
3. At least one of them is suitable mentally or materially.
Spiritual experience makes you have endless topics, while material experience makes your consumption view consistent and reduces a lot of friction. In the final analysis, only one level of people can get along for a long time. Class gap or cultural gap often makes one side feel inferior and the other side feel lonely.
Falling in love is easier than getting married. May you open your eyes and find the right person.