Which part of the following sentence contains a grammatical error? "She do not speak of either German or French."

Introduction / Context:
Error spotting questions in English grammar often focus on subject–verb agreement, prepositions and conjunctions. In this sentence, you are asked to identify the specific part that contains a grammatical error. The sentence describes someone who does not speak two particular languages, and one segment of the sentence breaks basic subject–verb agreement rules.

Given Data / Assumptions:

• The full sentence is: "She do not speak of either German or French."
• The options break the sentence into parts: "do not", "of", "or", "speak" and "either".
• We assume standard rules of English grammar, especially for present simple tense and subject–verb agreement.
• Exactly one segment contains the main grammatical error tested here.

Concept / Approach:
In the present simple tense, third person singular subjects such as "she", "he" or "it" require a verb form with s, as in "does" or "speaks". The correct negative form is "does not" or "does not speak", not "do not speak". Therefore, the phrase "do not" is incorrect when the subject is "she". The other parts of the sentence, while not perfectly elegant, are grammatically acceptable in this context and are not the focus of the error spotting.

Step-by-Step Solution:
Step 1: Identify the subject of the sentence, which is "She". This is third person singular feminine.Step 2: Check the auxiliary verb used in the negative: "do not". For third person singular in present simple, the auxiliary should be "does", not "do".Step 3: Recognise that the correct phrase should be "does not", making the grammatically correct sentence "She does not speak of either German or French."Step 4: Examine the word "of". While some style guides might recommend different wording such as "She does not speak either German or French", the preposition "of" is not the central grammatical error being tested.Step 5: Check "or", which correctly joins the two language options German and French.Step 6: Check "speak", which is the base form used after the auxiliary "does" in negative and question forms, so it is correct once the auxiliary is fixed.Step 7: Check "either", which is correctly used before the pair German or French to indicate one or the other of the two languages.Step 8: Conclude that the error lies in the phrase "do not".

Verification / Alternative check:
You can verify this by considering similar sentences. For example, "She does not play tennis", "He does not drive a car", and "It does not work properly" all use "does not" with third person singular subjects. The phrase "She do not speak" sounds clearly wrong when compared to these standard forms. However, "of either German or French" and the rest of the sentence follow normal patterns of English expression, even if some minor stylistic adjustments could be made. This confirms that "do not" is the only clear grammatical error.

Why Other Options Are Wrong:
The word "of" may feel slightly awkward to some readers, but it is not grammatically incorrect in all contexts, especially in informal speech. The conjunction "or" correctly joins two alternatives, German and French. The verb "speak" is appropriate after an auxiliary such as "does" in negative form. The word "either" is correctly used to indicate a choice between two items. Since none of these parts breaks a fundamental rule of subject–verb agreement, they are not the primary source of error in the sentence.

Common Pitfalls:
A common pitfall is to over focus on prepositions like "of" and suspect them whenever a sentence sounds slightly odd. Another mistake is to miss the subject–verb agreement error because the phrase "do not" appears often in English, but it is only correct with plural subjects or the pronoun "I". To avoid this, always match the subject type with the auxiliary: "I do", "they do", "we do", but "he does", "she does" and "it does". Remembering this pattern will help you quickly spot and correct similar errors in exam questions.

Final Answer:
The grammatically incorrect part of the sentence is do not.