Apart from conveying information to those around us when we communicate, we also convey where we stand with regards to this information, for example, we indicate our certainty about the information we divulge. To paint a clearer picture, how would you read these two sentences?

“The keys are on the table.”

“The keys are on the table?”

Despite containing the same words, the first sentence sounds more matter-of-factly, probably how your mom would sound when you ask her where your car keys are. The second sentence sounds more disbelieving, probably how you would sound after your mom tells you where your car keys are.

However, not much was known about how pre-schoolers (aged 3 to 5) signal their certainty of knowledge. This is the age at which children usually become very talkative, in addition to asking 'why' all the time.

This sparked the curiosity that led to a recently published study by Iris Hübscher for her doctoral research under the supervision of Pilar Prieto, coordinator of the Prosodic Studies Group (GrEP) and ICREA researcher at the Department of Translation and Language Sciences (DTCL) at UPF, alongside Laura Vincze, a member of the GrEP.

The aim of this study was to investigate how pre-schoolers signal their state of knowledge. "We approached the problem by evaluating the potential production of a series of prosodics (accent, tone and intonation) and lexical indices, which are known in adults to express uncertainty", said Hübscher, first author of the work. The researchers also noted how children self-assess their state of knowledge.

The results revealed that pre-schoolers use a series of variations in their speech. This could be in the form of varying their pitch, rhythm or tempo when speaking, or even lengthening their words, just to name a few.

It is likely that 3-year-olds express their uncertainty by varying their intonation.

Moreover, it has been observed that children use all sorts of other gestures: raised eyebrows, head tilts and facial signs such as frowning and tightening of the lips. The combination is endless and simply depends on how sure or unsure they are.

Researchers said, "We have seen that at the age of 5, children began to use a limited number of lexical markers, which are missing in the younger age group". Markers such as verbs ("I think") or adverbs ("perhaps/maybe") were more common amongst the older children.

The study debuts the abundance of gestural and speech variables of children at the age of 3 in order to express their degree of knowledge or uncertainty about their environment.

In this representational photo, a mother sits next to her three-year-old daughter on a park bench as the girl drinks orange juice in Berlin, Germany, Sept. 16, 2012. Adam Berry/Getty Images