1. Write down your activities. Which are more important? Do them.

2. Write down your activities. Which is more important? Do them.

(Which one is right? Do we have to use 'Which are' or 'Which is'?)

3. Summer break is over.
4. Summer vacation is over.
5. Summer holiday is over.
(If a student says the expressions above, do they have the same meaning? [from 3-5])

#1 is right if there are three or more activities or maybe an unknown number of activities.

#2 is right if there are only two activities (no other number!).

"Which are" is correct since you're referring to "activities" (plural).

3 - 5 are all about the same, yes.

You would use "Which is" if you want to choose just one.

If you may choose more than one, you would use "which are".

3-5 all mean the same thing and all are used.

1. Both forms of the sentence can be correct, depending on the context. Let's break it down:

- "Write down your activities. Which are more important? Do them."
This form is appropriate when you expect the person to have multiple activities, and you want them to prioritize and focus on the activities that are more significant or urgent.

- "Write down your activities. Which is more important? Do it."
This form is suitable when you expect the person to have one main activity or task to prioritize and complete.

The choice between using "which are" or "which is" depends on whether you are referring to multiple activities (use "which are") or a singular activity or task (use "which is"). Consider the context and use the appropriate form accordingly.

2. Regarding the meaning of "Summer break," "summer vacation," and "summer holiday":

- "Summer break" is a term commonly used in educational settings to refer to the time off that students have during the summer months. It typically implies a break from academic studies, allowing students to relax or engage in other activities.

- "Summer vacation" is a more general term that is used to describe a period of time, usually during the summer months, where people take time off from work, school, or regular routines to rest, travel, or engage in leisure activities.

- "Summer holiday" is a term primarily used in British English and other Commonwealth countries. It refers to the time when schools close for the summer and people take a break from work or other obligations.

While these terms may have slightly different connotations and regional usage, in general, they all refer to the end of the summer period, indicating a return to regular routines or responsibilities.