Learn Hardcore Russian: Она говорит, что каждый волонтёр старается выгуливать собак хотя бы раз в неделю. - She says that every volunteer tries to walk the dogs at least once a week.

Russian always puts a comma before что when it starts a subordinate clause like this.
Unlike English, where you can sometimes drop "that" (e.g. "She says everyone tries..."), in Russian что cannot be omitted and the comma is mandatory in standard writing.

Does она говорит mean “she says”, “she is saying”, or “she said”? How does this tense work?

Она говорит is present tense and covers both:

She says (general, repeated, or current statement)
She is saying (right now)

Russian does not have a separate continuous form like “is saying”, so present tense говорит covers both simple and continuous meanings, depending on context.

If you want she said, you must change the verb to past tense:

Она сказала, что каждый волонтёр старается... = She said that every volunteer tries...

What is the difference between каждый волонтёр and все волонтёры?

Both can be translated as something like “every volunteer / all the volunteers,” but there is a nuance:

каждый волонтёр = each individual volunteer, one by one
- Emphasizes the action of each person separately.
все волонтёры = all the volunteers as a group
- Emphasizes the group as a whole.

So:

каждый волонтёр старается… = each volunteer makes an effort…
все волонтёры стараются… = all (the) volunteers make an effort…

In this sentence, каждый underlines that it applies to every single volunteer, not just “most volunteers” or “the group generally.”

Why do we need старается here? Why not just say каждый волонтёр выгуливает собак…?

Стараться means “to try / to make an effort”. The pattern is:

стараться + infinitive
- старается выгуливать = tries to walk (the) dogs

Difference in meaning:

каждый волонтёр выгуливает собак…
- every volunteer walks the dogs… (a plain fact, no nuance of effort)
каждый волонтёр старается выгуливать собак…
- every volunteer *tries to walk the dogs…* (they make an effort, even if it doesn’t always work out)

So старается adds the idea that they aim for this and put in effort, not just that it unquestionably happens.

What does the -ся in старается mean?

The -ся ending marks a reflexive verb in Russian. Стараться is always reflexive; there is no non-reflexive form старать with the same meaning.

стараться = to try, to make an effort
Forms: я стараюсь, ты стараешься, он/она старается, мы стараемся, etc.

Here it does not mean “trying oneself” in a literal, physical sense; it’s just part of the verb’s normal form and must always be there.

Why is it выгуливать and not выгулять or just гулять?

Three points:

Aspect (imperfective vs perfective)
- выгуливать – imperfective (ongoing, repeated, habitual)
- выгулять – perfective (completed, one-time result)
For actions that are regular/habitual (like “once a week”), Russian uses the imperfective:
- старается выгуливать собак хотя бы раз в неделю
  = tries to walk the dogs (regularly) at least once a week
Выгулять would sound like focusing on one entire completed walk, not a habit.
гулять vs выгуливать
- гулять = to walk / to stroll (generally)
- выгуливать кого? = to walk (an animal)
With dogs, the normal verb is выгуливать (собаку / собак), specifically “take a dog/dogs out for a walk.”
Construction with стараться
- After стараться + infinitive with a habitual meaning, the imperfective (выгуливать) is the natural choice.

Why is it собак, not собаки or собаку?

This is about case and number:

The verb выгуливать takes a direct object in the accusative case:
- выгуливать кого? что? – to walk whom/what?
Собаки (nominative plural) → “dogs” as the subject.
- Собаки лают. – The dogs are barking.
Собак here is accusative plural (animate), which for animate nouns looks like the genitive plural form:
- Nominative plural: собаки
- Genitive plural: собак
- Accusative plural (animate): собак

So:

выгуливать собак = to walk dogs (direct object, plural, animate)

Собаку would be singular – to walk a dog. The sentence chooses plural because it’s talking about walking dogs in general or multiple dogs.

What does хотя бы mean, and how is it different from just saying раз в неделю?

Хотя бы means “at least”. It suggests a minimum acceptable amount, often with a hint that more would be better.

Compare:

раз в неделю = once a week (neutral statement of frequency)
хотя бы раз в неделю = at least once a week
- Implies: it would be good if it were more often, but once a week is the minimum they aim for.

So хотя бы adds the nuance of minimal standard / minimal expectation.

How does раз в неделю work? Why use в and not something like на неделю?

Раз в неделю literally is “(one) time in a week” and is a standard Russian pattern for frequency:

раз в день – once a day
два раза в неделю – twice a week
три раза в месяц – three times a month

The preposition в here means “per” or “in (each)”, much like “a” in English “once a week”.

Using на неделю would mean “for a week” (duration), which is different:

уехать на неделю – to go away for a week (duration)
раз в неделю – once a week (frequency)

So раз в неделю is the correct structure for how often something happens.

Can the word order in the second part be changed, or must it be каждый волонтёр старается выгуливать собак хотя бы раз в неделю?

Russian word order is flexible, so several orders are possible, with slight changes of emphasis. All of these are grammatically fine:

каждый волонтёр старается выгуливать собак хотя бы раз в неделю
каждый волонтёр хотя бы раз в неделю старается выгуливать собак
каждый волонтёр старается хотя бы раз в неделю выгуливать собак

The basic recommended learner-friendly order is the one you have: subject → verb → infinitive → objects/adverbials.

You cannot freely break up каждый волонтёр or move words in ways that sound unnatural, for example:

✗ волонтёр каждый старается… (very unusual and awkward here)

Stick to the given structure or the slight variants above.

Why is there no word for “their” before “dogs”? Could we say своих собак?

Russian often omits possessive pronouns when it’s obvious whose thing is being talked about, especially with typical relationships (one’s own body, own children, own pets, etc.).

выгуливать собак in this context naturally implies “walk (their) dogs.”

If you say:

старается выгуливать своих собак хотя бы раз в неделю

it becomes very explicit that these are their own dogs. This is correct and natural, just slightly more specific than needed in a general statement about volunteers and dogs.