Fill in the blank with the most appropriate word.
Last night I ________ you, but the phone was out of order.

The sentence "Last night I ________ you, but the phone was out of order." describes a situation where the speaker attempted to contact someone by phone. The past tense form "phoned" is the most appropriate choice to fill in the blank. This indicates that the speaker made an effort to call the person, but their attempt was unsuccessful because the phone was out of order. The usage of "phoned" in the past tense accurately conveys the idea that the action was performed, even though it did not yield the intended result due to the phone's malfunction.

Option A: would phone
This option is incorrect. "Would phone" is not suitable in this context, as it implies a hypothetical or conditional action, rather than a past attempt to call.

Option C: were going to phone
This option is incorrect. "Were going to phone" indicates an intention in the past, but it does not convey that the actual action of phoning took place.

Option D: did phone
This option is incorrect. "Did phone" is grammatically correct, but it does not capture the fact that the attempt to phone was unsuccessful due to the phone being out of order.

Option E: didn't phone
This option is incorrect. "Didn't phone" implies that no attempt to call was made, which contradicts the context of the sentence where the speaker tried to call but couldn't due to the phone being out of order.

The correct answer is Option B: phoned, as it accurately represents the past action of attempting to call someone, despite the unsuccessful outcome due to the malfunctioning phone.