"Plethora" is a singular noun, so you say "is a plethora."
no
up has plethora of menaings in English alone. the direction "up" translates uvirkh. go and please your ukrainian woman with your knowledge of her tongue.
Your girlfriend could be right technically based on her experience. People say things they have knowledge of. To proof her knowledge you can do a small research.
Plethora is singular and the plural form is plethoras
Knowledge and attitude are two objects that can never be weighed on the same weighing balance. The former defines the latter and vice versa . On the whole we can say that right knowledge brings the right attitude or with right attitude comes the right knowledge. Seeking inspiration from the epic Ramayana, Ravana was a mastermind but his lack of right attitude led to his ruin. Employers look for people with good knowledge who possess the attitude to utilize their knowledge to the fullest.
(Plethora means an abundant excess as a bountiful excesss such as riches.)"The Thanksgiving feast was a plethora of favorite foods of the family.""There was a plethora of costumes to choose from for the masquerade.""From the plethora of possible names for the project, he chose the most apt."
There was a plethora of food on the table at Thanksgiving.
"Is", since plethora is in singular form
Plethora is a noun.
The noun plethora (a plethora) uses singular verb forms.The word plethora is an uncountable (mass) noun, a type of aggregate noun that refers to an unspecified but large number of elements, e.g. a plethora of choices.
No, it is spelled knowledge.