When I asked Rachel Sussman, a a relationship expert and marriage counsellor in New York City, about the most common fights couples have, she started mentioning things like chores and social media. I was sceptical. These issues seemed relatively trivial, especially compared to infidelity or a clash in parenting styles.

But Sussman explained that the fight isn’t so much about the issue itself as it is about a lack of communication. “If you’re someone who has really poor communication skills,” she told me, “that might mean that the minute your partner brings something up, you get very defensive, or you start with the ‘tit for tat.’” Which means that “no matter what you’re arguing about, that could escalate into a really big fight.”

Sussman described 10 of the most common sources of conflict among the couples she sees — and importantly, she said, working on your communication skills is the key to resolving them all. “If you can communicate well, you can get through these issues in a way that can actually bring you closer together,” she said. “And if you can’t communicate well, it makes it so much worse and can actually tear you apart.”

Commitment

When unmarried couples come to see Sussman, they often want to talk about commitment. Typically, Sussman said, one partner feels like they’re more committed than the other. Or, one partner wants to “move the relationship forward” by moving in together or getting engaged and is encountering some resistance.

Chores

If couples are fighting about household chores, Sussman said, it’s probably because “one person feels like they’re taking the lion’s share of the work.”

In Sussman’s experience working with heterosexual couples, that person is usually the woman. Meanwhile, she added, “I often hear the men feeling that they’re doing a lot but they don’t get credit for it. They get picked on a lot.”

Indeed, according to a 2007 Pew Research poll, sharing household chores is the third most important factor in a successful marriage. (The first two are faithfulness and a happy sexual relationship).

And in an excerpt from “Fast-Forward Family” published 2013 in The Atlantic, three researchers write that even today, women still tend to shoulder the brunt of their family’s housework.

Social media

Sussman said she’s seen a spike in the number of complaints about a partner’s social media habits in the last five years. Typically, couples with these kinds of problems are in their twenties and thirties.

One person might complain, for example, “that their life is plastered all over social media or they think their partner is addicted to their phone.” Sussman’s also heard from people who are worried that their partner is following a ton of models on Instagram.

Another common issue? Staying in touch with an ex on social media.

Finances

“It’s very normal in a couple that one person is a spender and one is a saver,” Sussman said. The problem is “you think you’re justified and the other person is at fault.” The saver might accuse the spender of being fiscally irresponsible; the spender might accuse the saver of being cheap.

Don Cloud, president and founder of Cloud Financial Inc., previously told Business Insider that he frequently works with spender and saver couples. The first step, he said, is for each partner to share their beliefs and feelings about money.

Yet Sussman said issues also tend to arise when couples move in together or get married and face the decision about whether to combine finances, a notoriously difficult choice. If they’re hesitant, “might this show that there’s a lack of trust?”