Unnecessary Definite Article
If the noun is general, an indefinite article – or possibly no article – may be used.
Use the utensil when eating the dinner.
Use the fork when eating your dinner.
Use a utensil when eating dinner.
Give me the liberty or give me the death.
Give me liberty or give me death.
Remember that a noun which has been previously mentioned must be modified by a direct article; however, if the noun is just popping up for the first time, an indirect article should be used.
A child is riding a bicycle along a sidewalk; the child is wearing the helmet.
The first the (in the second clause) is correct because child has already been mentioned; we know the writer is talking specifically about the child who is riding a bicycle. The second the should be replaced by an indefinite article (a) because we don’t know which helmet the child is wearing.
N.B. Sometimes the article will change the meaning of the sentence. For instance, if I wrote “I need to buy a new pen for the school”, it might imply that I have broken one of the school’s pens and need to replace it. However, if I am buying it for myself to use in school, “the” should be removed from the sentence: “I need to buy a new pen for school.”