Improve the underlined part in the sentence "The footballers (has been) arguing with the coach since morning." by choosing the correct verb form.

Introduction / Context:
This sentence improvement question tests subject verb agreement and correct use of present perfect continuous tense. The sentence describes an action that started in the past (since morning) and continues up to the present time. The subject "The footballers" is clearly plural, so the verb phrase must agree with that.

Given Data / Assumptions:
The original sentence is: "The footballers has been arguing with the coach since morning." The options for the underlined part "has been" are:

• was
• had been
• have been
• no improvement

We assume the intended meaning is that the arguing started in the morning and is still going on or has very recently stopped.

Concept / Approach:
The important grammar points are:

• Plural subject "footballers" requires a plural auxiliary verb "have", not "has".
• The phrase "since morning" signals that present perfect or present perfect continuous is appropriate when the action extends to the present.
• "Has been arguing" is singular; "have been arguing" is plural.

Step-by-Step Solution:
Step 1: Identify the subject: "The footballers" is plural because it refers to more than one player. Step 2: Recognise that the action started in the morning and continues: "since morning" typically goes with perfect tenses. Step 3: The structure needed is plural present perfect continuous: "have been arguing". Step 4: Compare options: "was" (simple past, singular), "had been" (past perfect), and "no improvement" (retaining incorrect "has been"). Only "have been" fits both number and tense requirements.

Verification / Alternative check:
Try the corrected sentence: "The footballers have been arguing with the coach since morning." This clearly expresses that the group of players started arguing earlier and the arguing has lasted up to now. If we try "was arguing", the subject verb agreement fails. "Had been arguing" would place the entire activity before some other past reference point, which is not indicated in the sentence.

Why Other Options Are Wrong:

• was: Singular and in simple past, so it disagrees with plural "footballers" and loses the continuation idea.
• had been: Past perfect continuous, which would require another past time marker ("before the match began") that is not present.
• no improvement: Keeps "has been", which is singular and therefore grammatically incorrect with a plural subject.

Common Pitfalls:
Students sometimes focus only on the tense keyword "since" and forget to check the subject. Others overuse "had been" whenever they see "since" or "for", but that is only correct when the reference point is in the past. Build a habit of first matching the subject and auxiliary, then choosing the correct tense for the time context.

Final Answer:
The correct improvement is have been, giving "The footballers have been arguing with the coach since morning."