**Rule**: The **Simple Past Tense** is used for a repeated, habitual action in a completed past period. **Correct Usage**: 'every day last week' describes a finished period of time during which the habitual action ('barked') occurred. **Incorrect Options**: (b) 'was barking' describes one specific instance. (c) 'had barked' would need another past reference. (d) 'barks' is a present tense.

**Rule**: The **Past Continuous Tense** describes an ongoing action that was interrupted by a sudden event. **Correct Usage**: The ongoing work on the project ('was working') was interrupted by the computer crashing ('crashed'). **Incorrect Options**: (a) 'worked' (Simple Past) suggests one action followed another. (c) 'had worked' and (d) 'had been working' would be used if the work happened before another past event, not a direct interruption.

**Rule**: The **Past Perfect Continuous Tense** is used to emphasize the duration of a situation leading up to another past state or event. The word 'only' can be added for extra emphasis on the short duration. **Correct Usage**: 'had only been living' emphasizes the short six-month period during which they 'had already made' many friends. **Incorrect Options**: (a) 'lived' is less descriptive. (b) 'were living' is the wrong sequence. (d) 'had lived' focuses on completion, not the ongoing state.

**Rule**: The **Simple Past Tense** is used for a completed action that took place at a specific time in the past. **Correct Usage**: 'last year' is a definite past time, requiring the Simple Past verb 'spent'. **Incorrect Options**: (b) 'were spending' describes the vacation in progress. (c) 'had spent' would need another past reference. (d) 'have spent' is a present tense.

**Rule**: The **Past Continuous Tense** is used to describe a background situation that was in progress and prompted a subsequent action. **Correct Usage**: The strange noise ('was sounding') was the ongoing situation that caused the driver to take action ('pulled over'). **Incorrect Options**: (a) 'sounded' (Simple Past) is also possible but less descriptive of the ongoing noise. (c) 'had sounded' and (d) 'had been sounding' would imply the noise had started before another past event.

**Rule**: The **Past Continuous Tense** can be used to describe an ongoing action or behavior that was evident at a particular time in the past. **Correct Usage**: 'It was obvious' describes the past situation. The reason it was obvious was his ongoing behavior of 'not telling' the truth at that time. **Incorrect Options**: (a) 'didn't tell' (Simple Past) is for a single instance. (c) 'hadn't told' would mean he had failed to tell it at a time prior to the situation. (d) 'doesn't tell' is a present tense.

**Rule**: The **Past Perfect Tense** is used to show that an action was completed before a specific time or another event in the past. **Correct Usage**: The action of eating the cookies ('had eaten') was completely finished before the mother's arrival ('got home'). The phrase 'By the time' is a strong indicator for this tense. **Incorrect Options**: (a) 'ate' (Simple Past) is less precise about the completion before the arrival. (b) 'were eating' (Past Continuous) means they were still eating when she arrived. (d) 'had been eating' would focus on the process of eating, not the completion.

**Rule**: The **Simple Past Tense** is used to report a completed past action or statement. **Correct Usage**: 'claimed' is the simple past action. The clause that follows ('had finished') is correctly in the past perfect, showing it happened before the claim. **Incorrect Options**: (b) 'was claiming' is an ongoing action. (c) 'had claimed' would imply the claim was made before another past event. (d) 'claims' is a present tense.

**Rule**: The **Past Perfect Continuous Tense** is used to emphasize the duration of a preparatory action before a contrasting past state. **Correct Usage**: He 'was' still nervous (past state) despite the fact he 'had been practicing' (long, continuous prior action) for a whole week. **Incorrect Options**: (a) 'practiced' is less descriptive. (b) 'was practicing' is the wrong sequence. (d) 'had practiced' (Past Perfect) is also possible.

**Rule**: The expression 'It was the first time...' is followed by the **Past Perfect Tense** to describe a new experience that happened in the past. **Correct Usage**: The structure 'It was the first time I had ever done something' is a fixed grammatical pattern for talking about a past milestone. **Incorrect Options**: (a) 'flew' (Simple Past), (b) 'was flying' (Past Continuous), and (d) 'fly' (base form) are all grammatically incorrect in this specific structure.