Pronunciation: [dˈə͡ʊst ɐ sˈɜːvɪs] (IPA) 
The correct spelling of "doest a service" is actually "does a service." The word "doest" is an outdated form of the present tense of "do," which is no longer in regular use. "Does," on the other hand, is the correct form, and is pronounced /dʌz/ in IPA phonetic transcription. The word "service" is pronounced /ˈsɜːrvɪs/ in IPA phonetics, and refers to an act of help or assistance provided to someone.
"Doest a service" is an archaic phrase derived from Middle English that is no longer commonly used in modern English. It is the combination of the verb "doest," the second-person singular present tense of "do," and the noun "service."
In its historical context, "doest a service" refers to the act of performing or carrying out a helpful or beneficial action for someone. This phrase typically implies providing assistance, support, or aid to someone in need, often willingly or out of a sense of duty. It can encompass a wide range of actions, such as running an errand, completing a task, or offering a favor.
The use of the verb "do" emphasizes the execution or accomplishment of the service, while the noun "service" focuses on the act being performed. Together, this phrase suggests an act that contributes positively to another person's well-being or satisfaction.
While "doest a service" is not widely used today, it showcases an older form of English language and syntax. The phrase encapsulates the concept of performing a favor or helpful act for someone, indicating a sense of duty, kindness, or responsibility towards others.
