In this English grammar item on Direct and Indirect Speech, convert the sentence "My friend said to me, 'I am willing to help you on a condition.'" into the correct Indirect Speech form.

Introduction / Context:
This question deals with changing a statement from Direct Speech to Indirect Speech. The direct sentence is: My friend said to me, "I am willing to help you on a condition." You need to choose the reported form that correctly applies tense change, pronoun change and removes quotation marks while preserving the original meaning. This is a common pattern in English grammar questions on reported speech.

Given Data / Assumptions:

- Reporting clause: My friend said to me. - Reported clause: I am willing to help you on a condition. - Reporting verb: said, in the past tense. - The speaker in the reported clause is my friend, not the narrator. - The listener is me and appears as you in the original direct speech.

Concept / Approach:
When changing statements from direct to indirect speech with a past reporting verb, present continuous or present simple tense normally shifts to a corresponding past form. Here the verb phrase is am willing, which is in the present tense. In indirect speech it typically becomes was willing when the reporting verb is in the past. The pronoun I, which refers to my friend, changes to he in indirect speech. The pronoun you, which refers to the listener me, changes to me. The conjunction that is usually inserted after said to link the reporting and reported clauses.

Step-by-Step Solution:

Verification / Alternative check:
To check, convert the indirect version back into direct speech. Starting from My friend said to me that he was willing to help me on a condition, we remove that, change he was willing back to I am willing, and change me back to you. The sentence becomes My friend said to me, "I am willing to help you on a condition." This matches the original sentence, which confirms the correctness of the transformation.

Why Other Options Are Wrong:
Option A uses is willing instead of was willing, failing to change the tense after a past reporting verb. Option B contains the ungrammatical phrase has had been willing, which is incorrect and unnecessarily complex. Option C uses has been willing, which is present perfect continuous and does not match the simple present sense of the original. Option E uses would be willing, which suggests a new future or hypothetical willingness rather than reporting the present willingness expressed earlier. Option D correctly shifts the tense and pronouns, so it is the best answer.

Common Pitfalls:
Many students either forget to shift the tense when the reporting verb is in the past or they overcomplicate the tense change by adding unnecessary auxiliary verbs. Another common error is mishandling pronouns; if you do not carefully identify who is speaking and who is listening, you may keep I and you unchanged, which produces an incorrect reported sentence. Always identify the speaker, the listener and the time reference before you start changing the sentence to indirect speech.

Final Answer:
The correct indirect speech form is My friend said to me that he was willing to help me on a condition.