**Rule**: **Stative Verbs**. When 'see' means 'understand' or 'realize', it is a stative verb and is used in the **Simple Present Tense**. **Correct Usage**: 'I see you're busy' is a polite way of saying 'I understand/realize you're busy'. **Incorrect Options**: (b) 'am seeing' would be for the physical act of looking. (c) 'have seen' refers to a past visual experience. (d) 'sees' is for a third-person singular subject.

**Rule**: Both **Present Perfect ('has worn')** and **Present Perfect Continuous ('has been wearing')** are used for states that began in the past and continue to the present. For long-term states like 'wear' or 'live', the Present Perfect Simple is very common and natural. **Correct Usage**: 'has worn' correctly describes the long-term state that started in the past and continues now. **Incorrect Options**: (a) 'wears' (Simple Present) doesn't emphasize the duration. (b) 'is wearing' (Present Continuous) is for the present moment. (c) 'has been wearing' is also correct and emphasizes the continuous action.

**Rule**: The **Present Perfect Continuous Tense** is used to explain a present result ('The children are dirty') by emphasizing the recent, continuous action that caused it. **Correct Usage**: 'have been playing' shows the duration and continuity of the action (playing in the mud) that led to their current state of being dirty. **Incorrect Options**: (a) 'play' (Simple Present) is a habit. (b) 'are playing' (Present Continuous) means they are still playing. (c) 'have played' (Present Perfect) is also possible, but 'have been playing' better emphasizes the activity that caused the dirt.

**Rule**: The **Simple Present Tense** is used to state a fact about something, like the duration or a characteristic of a movie, book, or play. **Correct Usage**: 'lasts' states a fact about the film's running time. The subject 'This film' is singular. **Incorrect Options**: (b) 'is lasting' and (c) 'has been lasting' are incorrect because 'last' (meaning to have a duration) is typically a stative verb. (d) 'last' is for plural subjects.

**Rule**: The **Present Continuous Tense** is used for an action in progress at the moment, which is the reason for a present situation ('doesn't want to be disturbed'). **Correct Usage**: 'is listening' correctly describes the current activity that requires concentration. **Incorrect Options**: (a) 'listens' (Simple Present) is a habit. (c) 'has listened' (Present Perfect) is a completed action. (d) 'has been listening' would emphasize the duration.

**Rule**: The **Present Continuous Tense** is used for an action in progress at the moment of speaking, which has an effect on the present situation. **Correct Usage**: The warning 'be careful where you walk' is given because the children 'are playing' in the garden right now. **Incorrect Options**: (a) 'play' (Simple Present) is a habit. (c) 'have played' (Present Perfect) means the game is over. (d) 'have been playing' would also be possible if emphasizing the duration of the game.

**Rule**: **Stative Verbs**. When asking for an opinion, 'think' is a stative verb and the question is formed using the **Simple Present Tense**: **(Wh-word) + do/does + subject + think?**. **Correct Usage**: 'do you think' is the correct way to ask for someone's current opinion. **Incorrect Options**: (a) 'are you thinking' asks about the cognitive process happening in their head right now, not their opinion. (c) 'have you thought' asks about their thought process up to this point. (d) 'you think' is not a proper question form.

**Rule**: **Stative Verbs**. 'Seem' is a stative verb used to express an impression. It is used in the **Simple Present Tense** to describe a current state. **Correct Usage**: 'seem' correctly conveys the impression the person is giving right now. The subject 'You' takes a plural verb form. **Incorrect Options**: (b) 'are seeming' is grammatically incorrect. (c) 'have seemed' is the wrong tense. (d) 'seems' is a singular verb.

**Rule**: The **Present Perfect Continuous Tense** is used to talk about a past action that has been going on for a period of time and has a result in the present. **Correct Usage**: The present result is 'He seems tired'. The reason is the continuous action of studying that has just finished or is still ongoing. 'has been studying' perfectly connects the past action with the present result. **Incorrect Options**: (a) 'studies' (Simple Present) describes a habit. (b) 'is studying' (Present Continuous) doesn't connect to the past duration. (c) 'studied' (Simple Past) disconnects the action from the present result.

**Rule**: The **Simple Present Tense** is used to describe habits and daily routines. The phrase 'every afternoon' clearly indicates a repeated, habitual action. **Correct Usage**: 'takes' is the correct verb for the third-person singular subject 'My grandfather'. **Incorrect Options**: (a) 'is taking' (Present Continuous) means he is taking a nap right now. (b) 'has taken' (Present Perfect) means he has just finished his nap. (d) 'take' is for plural subjects.