John Legend is still learning about parenthood.

Chrissy Teigen and John Legend

Chrissy Teigen and John Legend

The 38-year-old singer-songwriter has 19-month-old daughter Luna with his model wife Chrissy Teigen, but John has admitted he's still adjusting to the day-to-day stresses of parenthood.

John - whose wife recently announced via Instagram that she's expecting their second child - explained: "I don't know if there were a lot of surprises. You're just really learning every day.

"Part of it is learning how to parent together, because even though Chrissy and I have been together for a long time, we haven't been parents together until the last year. I think you start to learn how to parent together and what kind of responsibilities you want to share and take on."

The chart-topping star revealed he's been fascinated to see Luna's development at first hand.

In particular, he's been "excited" to witness all of the little milestones she's already achieved in her young life.

Speaking to 'Entertainment Tonight', John shared: "It's really just fascinating watching the human mind develop and seeing what they pick it up and how quickly they pick it up.

"When they start walking, when they start crawling. How excited you are just when they start to turn over for the first time by themselves, all these little milestones that might seem silly to some people who don't have kids are really exciting for us.

"And I think just watching her grow has been the most exciting thing. And when you start to see a personality develop, it's just really cool."

And the 'All of Me' hitmaker - who's been married to Chrissy since 2013 - insisted he'll support his children in whatever career path they choose to follow.

He said: "I want them [Luna and the baby on the way] to find what they're passionate about and commit to it. Whatever it is, I'll support them.

"I love when Luna plays around with the piano, and I love when she plays with her little toy microphone that my friend bought her for her birthday. I get excited when it looks like she's following in my footsteps."