Pronunciation: [ɑː djˈuːbɪəs] (IPA) 
The spelling of the word "are dubious" may be confusing to English learners due to the pronunciation of "dubious." In IPA phonetic transcription, it is /ˈdjuːbiəs/. The "dju" sound represents the "j" sound, and the "i" and "o" combine to make the "u" sound. This word means uncertain or doubtful. To use in a sentence: "The reliability of the source 'are dubious,' according to the research team."
When used in the phrase "are dubious," the verb "are" refers to the third person plural form of the verb "to be," indicating the state or condition of something or someone. On the other hand, the adjective "dubious" describes a level of uncertainty, skepticism, or doubt regarding the trustworthiness, validity, or truthfulness of a particular thing, idea, or situation. "Are dubious" implies that multiple people, groups, or objects possess this sense of hesitation or lack of conviction.
To elaborate, "are dubious" suggests that there is a collective opinion or feeling characterized by a lack of confidence or reliability. It implies that the subject of discussion is questionable, potentially causing skepticism, suspicion, or a sense of unease. The adjective "dubious" conveys a sense of hesitancy or doubt, often based on incomplete or contradictory information.
For instance, if a group of researchers disagrees on the accuracy of certain scientific findings, it can be said that they "are dubious" about the validity of the results. Similarly, if a jury is uncertain about the credibility of a witness's testimony, the phrase "are dubious" might be applied to describe their sentiment towards the witness's credibility.
Overall, "are dubious" conveys a collective state of skepticism, uncertainty, or doubt surrounding a subject, highlighting the lack of trust or confidence in that particular matter by multiple individuals or entities.
The word dubious originated from the Latin word dubiosus, which means doubtful or uncertain. In Latin, dubium defined doubt or hesitation. Over time, this Latin word was borrowed into Middle English as dubious, with the same meaning. The word has retained its core sense of uncertainty and doubt throughout its usage history. As for the phrase are dubious, it is simply the combination of the present tense of the verb are (from Old English origin) and the adjective dubious.
