Learn Hardcore Russian: Новая грамматическая тема: глаголы движения «идти / ходить» и «ехать / ездить» — один раз сейчас или обычно много раз. - New grammar topic: the verbs of motion “идти / ходить” and “ехать / ездить”

глаголы is nominative plural of глагол (verb).
движения here is genitive singular of движение (movement, motion), so the structure is “verbs of motion,” like an English of-phrase.

It’s a fixed grammatical term in Russian; you will always see глаголы движения for “motion verbs.”

Why is it Новая грамматическая тема, with -ая endings, and not something like новый грамматический тема?

Because тема (topic) is a feminine noun. Adjectives have to agree with the noun in gender, number, and case:

тема – feminine, singular, nominative
новая – feminine, singular, nominative of новый (new)
грамматическая – feminine, singular, nominative of грамматический (grammatical)

So all three words match: Новая + грамматическая + тема.

What is the function of the colon after Новая грамматическая тема?

The colon works almost exactly like in English here:
Новая грамматическая тема: глаголы движения…

It means “New grammar topic: (namely) motion verbs…”.
So the part after the colon explains / specifies what the new topic is.

Why is there an em dash (—) before один раз сейчас или обычно много раз?

The em dash here introduces a short explanation of how these verbs are used:
… «идти / ходить» и «ехать / ездить» — один раз сейчас или обычно много раз.

You can read it as: “motion verbs ‘идти / ходить’ and ‘ехать / ездить’ — (that is, they describe) one time now or usually many times.”
So the dash links the verb pairs to their usage description.

Why are the verbs written in pairs идти / ходить and ехать / ездить?

Each pair contrasts two related motion verbs:

идти vs ходить – going on foot
ехать vs ездить – going by transport / vehicle

Within each pair:

the first (идти, ехать) is one direction / one trip, often “(going) now”;
the second (ходить, ездить) is repeated / habitual / in various directions, often “(go) usually, regularly”.

That’s why they are shown as pairs: they are systematic contrasts you have to learn together.

What is the difference between идти and ходить in simple terms?

Very simplified:

идти – to go (on foot) in one direction, one trip, typically happening now
- Я иду домой. – “I’m going home (right now, walking).”
ходить – to go (on foot) regularly, many times, or in different directions
- Я хожу в спортзал. – “I go to the gym (regularly).”

So this sentence sums it up as: один раз сейчас (идти) vs обычно много раз (ходить).

And what is the difference between ехать and ездить?

Same contrast, but by transport:

ехать – to go / ride by transport in one direction, one trip, usually now or planned
- Я еду на работу. – “I’m going to work (by bus/car etc.)”
ездить – to go / travel by transport regularly, many times, or in different directions
- Я часто езжу в Москву. – “I often go to Moscow (by transport).”

Again, this matches один раз сейчас (ехать) vs обычно много раз (ездить).

Why are the verbs given in the infinitive form (идти, ходить, ехать, ездить) instead of forms like иду, хожу, еду, езжу?

The infinitive is the standard dictionary form in Russian, like “to go, to read” in English.
When a grammar topic is introduced, verbs are usually listed in the infinitive:

идти – “to go (on foot, one direction / one occasion)”
ходить – “to go (on foot, habitually / many times)”

The actual sentence is functioning like a headline or section title, so it just lists the verbs in their base form.

Are these verbs about tense (present, past, future) or about something else?

In this context they are not about tense; they’re about type of movement (single vs repeated, one direction vs various directions).

All four verbs here (идти, ходить, ехать, ездить) are imperfective infinitives.

Tense (present/past/future) appears when you conjugate them (иду, шёл, буду идти, etc.).
The distinction shown in the sentence is один раз сейчас vs обычно много раз, which is the basic idea behind determinate vs indeterminate motion verbs.

Is this the same as the perfective / imperfective aspect contrast?

No, it’s a different contrast.

Pairs like читать / прочитать (to read / to read through) are imperfective vs perfective aspect.
Pairs like идти / ходить, ехать / ездить are both imperfective.
They contrast determinate (one trip, one direction) vs indeterminate (habitual / multiple / various directions) motion.

So the sentence is about types of motion within the imperfective aspect, not about perfective vs imperfective.

What exactly do один раз сейчас and обычно много раз tell me about usage?

They are a very short mnemonic:

один раз сейчас – use идти / ехать when you talk about one concrete trip that is happening now (or as one focused event).
обычно много раз – use ходить / ездить when you talk about usual, habitual, or repeated trips, or going in general.

This is simplified, but it captures the basic beginner rule: single specific trip vs repeated / usual trips.

Why is движения not движений if we are talking about more than one movement?

In the fixed term глаголы движения, движения is understood as “movement as a concept,” not “many individual movements.”

Grammatically:

движения here is genitive singular: “verbs of movement (in general)”.
Using движений (genitive plural) would sound like “verbs of movements,” which is not the standard term.

So you should remember the established phrase глаголы движения, with движения in genitive singular.

Why is there no verb like есть (“is/are”) in this sentence?

Russian often omits the verb “to be” in the present tense, especially in:

headings, titles, labels
definitions and short “X – Y” style sentences

Here the whole line works like a title:
“New grammar topic: motion verbs идти / ходить and ехать / ездить – one time now or usually many times.”

Adding есть would be grammatically possible but stylistically unnecessary and unusual in a textbook heading.

Why are the Russian quotation marks « » used around the verbs?

« » are the standard Russian quotation marks, similar to English “ ”.

Here they are used to set off the verbs идти / ходить and ехать / ездить as terms / examples within the sentence.
In printed Russian, especially in textbooks, you will very often see « » around words that are being mentioned, defined, or highlighted.