Nowadays, researchers are getting more and more interested in studying first language acquisition. Child-directed speech, which means the simplified talk of adults to children, has a significant role in the acquisition process. Different approaches can be found describing first language acquisition. The Behaviourist Approach claims that learning a language is a mere habit formation. The child repeats the utterances in order to get more positive feedback. Chomsky’s Nativist Approach challenged this type of analysis. It stated that language acquisition is more than habit formation. Based on a finite set of rules we are able to formulate infinite number of sentences and this would not be possible by learning bits of a language. Thus, children have to acquire the rules of a language and they have to go through several developmental stages. The interpretation of focus sentences is one of the aspects that children have to acquire when learning a first language. Two types of foci can be differentiated: identificational and information focus. The role of information focus is to mark new information of a sentence and it appears only prosodically. Contrastive to this, identificational focus changes the word order of a sentence. Exhaustivity is one of the features of identificational focus that has been debated in the recent years. Exhaustivity has the function to exclude the presence of other elements in a relevant set and it makes the predicate being true only for one particular subject. Linguists’ opinions are divided regarding the nature of focus. Some of them claim that the exhaustive interpretation is in connection with semantics and focus acts as a syntactic-semantic operator, while others state that it is not a semantic but a pragmatic phenomenon. No agreement can be found in this field. In recent years, experiments were conducted in order to investigate children’s sensitivity of focus. It was found that children use focus sentences quite early in their developmental stages. In one of the experiments, pre-school children were tested by Kas and Lukács (2013) and they found that children are able to interpret and make a distinction between focussed and non-focussed sentences to some extent. Their performance was not like adults’ but in some cases they performed nearly like adults did. The pilot study described above was aimed to find support for or against the hypothesis that children are sensitive to identificational focus. The children were randomly chosen from the Miskolc Szent Anna Óvoda and participated voluntarily. They took part in a sentence – picture verification task. They were shown pictures and had to decide whether the utterance they heard was true or false with respect to the picture. According to the results, children accepted both neutral and focus sentences in an exhaustive setting at a relatively high rate as they were expected. The acceptance rates for focus sentences in non-exhaustive setting were lower, but it does not allow us to suppose that children are sensitive to exhaustive focus. The results were similar to the Kas and Lukács study (2013). Further studies could be conducted in order to investigate this issue from a wider perspective.