Мы чуть было не поскользнулись на наледи.

Чуть было не means almost or came close to doing something, with the important idea that it did not actually happen.

So:

• Мы чуть было не поскользнулись = We almost slipped
• The slipping was very close, but in the end it did not happen.

This is a common Russian way to talk about a near-event.

That is a very common learner question. In чуть было не, the word было is part of a fixed expression and does not agree with the subject.

So even with:

• я
• ты
• мы
• они

you can still get чуть было не.

For example:

• Я чуть было не упал.
• Мы чуть было не опоздали.
• Они чуть было не проиграли.

Here было is not acting like a normal past-tense verb that changes with the subject. It is just part of the idiomatic phrase.

Поскользнуться means to slip in the sense of having a slipping incident. It is the normal verb for this situation.

Here it appears as:

• по-скольз-ну-лись
• past tense
• plural
• reflexive form

Why this form?

• мы = we
• past tense plural = -ли
• reflexive ending = -сь
• so: поскользнулись

Also, поскользнуться is perfective, which fits well with a single near-event: almost slipped.

By contrast, скользить usually means to slide / to be gliding / to slip along as a process, not one sudden slip.

The basic dictionary form is поскользнуться. The -ся / -сь is part of the verb itself.

In this case, it is best to learn поскользнуться as a whole verb meaning:

• to slip
• to lose one’s footing

It is not really translated as a literal reflexive in English. So don’t try to force a meaning like to slip oneself. Russian simply uses the reflexive form here.

Why -сь and not -ся?

• After a vowel, Russian often uses -сь
• After a consonant, -ся is more typical

So:

• поскользнулись
• not поскользнулися

Here наледи is used after на in the sense of location or surface: on the ice / on the icy patch.

So the idea is:

• на наледи = on an icy patch / on ice buildup

After на, Russian often uses:

• accusative for motion onto something
• prepositional for location on something

Here the meaning is location, so it is the prepositional case.

The noun is наледь, and one of its forms is наледи. In this sentence, that is the prepositional form.

Not exactly. Наледь is more specific than just лёд.

It usually means:

• a layer or buildup of ice
• slippery ice formed on a surface
• icy coating, often on roads, sidewalks, steps, or the ground

So наледь suggests dangerous, slippery surface ice rather than just ice in a general sense.

Compare:

• лёд = ice in general
• наледь = icy buildup / glaze / slippery ice on a surface

That makes it a very natural word in a sentence about almost slipping.

Yes, absolutely. Чуть не is very common and often means the same thing here:

• Мы чуть не поскользнулись на наледи.

This is a very natural alternative.

Very roughly:

• чуть не = simpler, very common almost
• чуть было не = also almost, but can sound a bit more expressive, narrative, or emphatic

In many everyday contexts, they are interchangeable.

Yes, мы could be omitted if the subject is clear from context:

• Чуть было не поскользнулись на наледи.

Russian often leaves out subject pronouns when they are understood.

But including мы is perfectly normal too. It can help by:

• making the subject explicit
• adding contrast or emphasis
• making the sentence clearer out of context

So both are possible.

Yes, Russian word order is flexible. The given version is neutral and natural:

• Мы чуть было не поскользнулись на наледи.

But other orders are possible, depending on emphasis. For example:

• Мы на наледи чуть было не поскользнулись.
• На наледи мы чуть было не поскользнулись.

These variants may emphasize where it almost happened.

Still, for a learner, the original order is a very good standard pattern:

• subject
• чуть было не
• verb
• place

Yes, поскользнуться is perfective, and that matters.

Perfective verbs in Russian often present an action as:

• a single whole event
• completed as one occurrence
• a specific incident

A slip is naturally a single event, so perfective fits well:

• поскользнуться = to slip once / have a slip

In this sentence, the event did not happen, but Russian still uses the perfective because it refers to the near-occurrence of one specific incident.

That is why чуть было не works very naturally with поскользнулись.

Depending on context, a natural English rendering could be:

• We almost slipped on the ice.
• We nearly slipped on the icy patch.
• We almost slipped on the ice buildup.

The most natural everyday translation is probably:

• We almost slipped on the ice.

Even though наледь is more specific than just ice, English often uses the simpler word unless the context specifically needs the more technical nuance.