The boy … the flute for about thirty minutes.

Analyze the question The sentence is "The boy _ the flute for about thirty minutes." The key clue is the phrase "for about thirty minutes", which shows a duration of time. We need the tense that fits this.

Explain the concept The present perfect continuous tense is used for an action that started in the past and has continued up to now (or has just stopped), especially when a duration is mentioned.

Structure: has/have + been + verb-ing

• He has been reading for two hours.
• They have been waiting since morning.

Solution: check each option

• A. was playing is past continuous. It describes an action in progress at a specific past time, and it doesn't naturally link to a duration with "for". It is possible in some contexts, but it is not the best fit here.
• B. has play is wrong. After "has", we need a past participle ("played") or "been + -ing", not the base form "play".
• C. has been playing is correct. It has the right structure (has + been + verb-ing) and fits the duration "for about thirty minutes".
• D. has being playing is wrong. It uses "being" instead of "been", which is a common spelling and grammar error.

Answer: The correct sentence is: "The boy has been playing the flute for about thirty minutes."

Exam tip When you see "for + a period of time" or "since + a point in time", think of the perfect tenses. If the action is ongoing or continuous, choose has/have been + verb-ing. Also, always watch out for the trap of "been" vs "being": the correct form after "has/have" is always been.