Новая грамматическая тема: вопросительная конструкция «стоит ли + инфинитив».

It is a very common Russian pattern for asking whether doing something is worth it, advisable, or a good idea.

So:

• Стоит ли идти? = Is it worth going?
• Стоит ли покупать это? = Is it worth buying this?
• Я не знаю, стоит ли ждать. = I don’t know whether it’s worth waiting.

It is called a вопросительная конструкция because it is used to form a question, either a direct one or an indirect one.

Yes, it is the same verb: стоить.

This verb can mean both:

• to cost
• to be worth

In стоит ли + infinitive, it has the meaning to be worth.

Examples:

• Это стоит 100 рублей. = It costs 100 rubles.
• Это стоит прочитать. = It is worth reading.
• Стоит ли читать это? = Is it worth reading this?

So this is a normal use of стоить, just with a different meaning.

Because ли usually comes after the word being questioned.

In стоит ли + infinitive, the thing being questioned is стоит:
Is it worth... ?

So Russian says:

• Стоит ли ехать?

not:

• Ли стоит ехать?

This is a very important rule for ли in Russian. It does not normally go at the very beginning of the sentence like English whether or if.

Because the construction talks about an action in general, not about a fully conjugated verb form.

So after стоит ли, you use the infinitive:

• читать
• идти
• ждать
• покупать

Examples:

• Стоит ли читать эту книгу?
• Стоит ли туда ехать?
• Стоит ли начинать сейчас?

You do not use a personal verb form after it:

• Стоит ли читаю... — wrong
• Стоит ли идём... — wrong

You usually add a dative pronoun or noun:

• Стоит ли мне идти? = Is it worth my going? / Is it worth it for me to go?
• Стоит ли нам начинать? = Is it worth our starting?
• Стоит ли студентам покупать эту книгу? = Is it worth students buying this book?

This is a very common pattern:

• мне
• тебе
• ему / ей
• нам
• вам
• им

So мне in Стоит ли мне идти? is not the subject in the English sense; it is the person for whom the action is relevant.

They are similar, but not the same.

• стоит ли = is it worth it? is it advisable?
• надо ли = is it necessary?
• нужно ли = is it needed? is it necessary?
• следует ли = should one...?; more formal

Compare:

• Стоит ли покупать эту книгу? = Is this book worth buying?
• Нужно ли покупать эту книгу? = Do I need to buy this book?
• Следует ли покупать эту книгу? = Should one buy this book?

So стоит ли is about value, usefulness, or good judgment, not strict necessity.

There are two important possibilities.

1. Не стоит + infinitive
   This usually means it is not worth doing or you shouldn’t do it.

• Не стоит спорить. = It’s not worth arguing.
• Не стоит туда ехать. = It’s not worth going there.

2. Стоит ли не + infinitive
   This means is it worth not doing something? or should one refrain from doing it?

• Стоит ли не отвечать? = Is it worth not answering?
• Стоит ли не вмешиваться? = Should one stay out of it?

So these are not the same:

• Не стоит ехать = It’s not worth going.
• Стоит ли не ехать? = Is it worth not going?

The most common form is the present:

• Стоит ли ехать?

But you can also use the past:

• Стоило ли ехать? = Was it worth going?
• Стоило ли это делать? = Was it worth doing?

For future situations, Russian often still uses the present form if the decision is being discussed now:

• Стоит ли мне ехать завтра? = Is it worth my going tomorrow?

So in practice, learners should first master:

• стоит ли + infinitive for present/future decisions
• стоило ли + infinitive for past evaluation

Because that phrase means interrogative construction or question construction.

• вопросительный / вопросительная = interrogative, question-related
• конструкция = construction, pattern

So the sentence is introducing a grammar topic: the Russian question pattern стоит ли + infinitive.

Because they agree with feminine nouns.

In Russian, adjectives must match the noun in gender, number, and case.

Here:

• тема is feminine, so we get новая грамматическая тема
• конструкция is feminine, so we get вопросительная конструкция

Also:

• инфинитив is masculine, so it appears in its masculine form as a noun.

So the endings are just normal adjective agreement.

The colon introduces an explanation or label.

So the sentence structure is basically:

• New grammar topic: [name of the topic]

This is very natural in both Russian and English when introducing a heading, lesson point, or definition.

Russian often uses «...» in printed text instead of English-style quotation marks.

These are called guillemets. In Russian textbooks and formal writing, they are very common for:

• titles
• terms
• named expressions
• quoted words or phrases

So «стоит ли + инфинитив» is just the named grammar pattern being introduced.