Holding a conversation with a five-year-old can be an adventure. One second you're sharing opinions on favorite breakfast cereals, the next they've jumped ship to something vague about a cartoon octopus.

What seems like a limited vocabulary or difficulty in keeping focused could actually be an inability to reconcile inferences with another person's perspective.

Researchers are discovering these two critical cognitive skills make it all but impossible for kids around five years old or younger to read between the lines of what seems like a simple conversation – one that involves something one person knows and the other doesn't.

"As parents or teachers, we need to remember that when children fail to get what adults mean, that may not just be because they don't understand the words," says University of Cambridge linguist Elspeth Wilson.

"Sometimes, the context of a conversation is too complex and children struggle to make the inferences they need."

What we take for granted in a conversation can rely heavily on a variety of skills that allow us to see the world through another's eyes.

Think about something as simple as asking the question, "What are you eating?" In the event the respondent says 'cereal', the questioner can reasonably assume they're not also eating bananas, toast, and a blueberry muffin. It's implied, even if not stated.

This skill of ad hoc implicature allows us to share information freely, without needing to build vast frameworks of context each and every time. While it seems straightforward, there's a lot of psychology packed into this basic unit of communication.

For one thing, it relies on the understanding that the person answering the question is providing the maximum amount of relevant information. The missing details are as important as the spoken ones.

This pragmatic language skill underpins interpersonal communication. Conditions such as autism spectrum disorder can greatly impede these skills, making it harder to see exactly how much detail to provide in any given context.

Implicature also assumes a level of shared knowledge on what both individuals can see or have experienced. A bowl of cereal on the table is clearly the subject of the question, for example, and not a list of items in the fridge.

As adults we integrate these two skills of pragmatic and epistemic reasoning with ease. But it raises an intriguing question – do these dual components of inquiry develop in conjunction, or do they emerge distinctly only to be woven together in time?

Going by some models, children can develop pragmatic communication strategies of providing relevant information while they're still limited to an egocentric view of their world. In other words, they don't need to take into account another's perspective to provide a relevant response.

Other models suggest there's a limited kind of theory of mind going on, where the tiny human attempts to read into the wording of your request even if they don't truly have a comprehension of your unique experience of the world.

To test these two conflicting hypotheses, researchers gathered 33 children aged five and six and engaged them in conversation using a puppet.

The puppet asked the child to pick cards based on what they displayed. In some cases, the card was clear to both the puppet and the child. In others, there was a relatively relevant card the puppet could see, as well as a more relevant card only obvious to the child.

For example, the puppet can see two cards – one with bananas and an apple, the other with apples and oranges; it asks for the card with bananas on it. However, from the child's perspective, in addition to the two cards seen by the puppet, there's also a card with bananas and nothing else.

Out of the whole group, only four children understood the puppet was referring to the card they both could see – with bananas and apples. Done with 36 adults, only nine failed to understand the puppet was implying the card they could both see.

While it's hard to know exactly what's going on in any of the participants' minds with certainty, the results seem to imply most children aren't effectively integrating the different skills together into ad hoc implicature.

Other tests conducted by the researchers with slightly older children aged between 5 and 7 years old demonstrate pragmatic and epistemic reasoning are in there somewhere, able to be practiced on their own. It just takes time for children to combine them into a single act.

For children just starting out in primary school, this could be an important developmental hurdle teachers need to take into account. Not all new students will be able to both reconcile the right response from their perspective with a relevant response from another's.

It's a good thing you know what that octopus cartoon is all about then, right?

This research was published in Language Learning and Development.