This is the 704th most frequent Swedish word.
allvarliga
Serious.
In this sentence, 'allvarlig' describes the tone of voice, implying that it was solemn or formal.
Hon talade med en allvarlig ton under mötet.
She spoke in a serious tone during the meeting.
Here, 'allvarlig' is used to describe the severity of the child's illness, suggesting its critical nature.
Barnets sjukdom är mycket allvarlig.
The child's illness is very serious.
The word 'allvarliga' is used here to mean 'serious' or 'severe', emphasizing the gravity of the problems faced by the subject.