Denzel Washington says the secret to his lasting marriage is marrying someone who ''knows about love''.

The 61-year-old actor has been with his wife Pauletta - with whom he shares four children, John, 32, Katia, 29, and 25-year-old twins Malcolm and Olivia - for 33 years, and says the secret to making things work is finding someone who knows the things he doesn't.

Speaking to American television program 'Extra', the actor said: ''I didn't know everything there was to know about love, but I married a woman who did and how to share that.''

The comments come as Denzel stars in drama movie 'Fences', which tells the story of a former professional baseball player named Troy Maxson (Denzel), when he creates tension in family after denying his teenage son's dream of playing football and comes home with the baby he had through an affair.

Recently, the Hollywood star claimed the movie - which was adapted from a play written by August Wilson that premiered in 1985 - has a relevant plotline 30 years later as ''it could happen to anyone''.

He said: ''The circumstances, again, are universal. It could happen to anyone. I don't know if it's more political now given the election or whatever, but it's a long way from Troy to now because now we're post-Obama even.''

Denzel also believes that despite the movie's predominantly black casting, the film features subject matters that are universal to anyone, regardless of their ethnicity.

Asked previously what insights into black lives 'Fences' gives to white Americans, Denzel said: ''It could be that it's not that different. Circumstances, no matter what the colour is, could be similar. Troy's whole [resentment of his lack of success as a baseball player] ... was it his colour or was he just too old? I think he was just too old regardless of his colour. Or, as his friends said, 'He just come along too early.' ''