Ik blijf liever thuis dan dat ik in de regen fiets.

Liever is the comparative form of graag.

With verbs, Dutch often uses this pattern:

• graag = gladly / with pleasure
• liever = rather
• liefst = preferably / most gladly

So:

• Ik fiets graag. = I like cycling.
• Ik blijf liever thuis. = I’d rather stay home.

A native English speaker may expect something like meer graag, but Dutch does not normally say that here. Liever is the standard word.

Because thuis blijven means to stay home, while thuis zijn means to be at home.

In this sentence, the speaker is expressing a choice between two actions:

• thuis blijven = stay home
• in de regen fietsen = cycle in the rain

So Ik blijf liever thuis focuses on the decision to remain at home, not just on the state of being there.

Here dan introduces the second part of a comparison: rather X than Y.

When the second part is a full clause with its own subject and verb, Dutch often uses dan dat:

• Ik blijf liever thuis dan dat ik in de regen fiets.

That structure is very common and very natural.

Compare:

• liever thuis dan op kantoor → after dan comes just a phrase
• liever thuis dan dat ik in de regen fiets → after dan dat comes a full clause

In less formal or alternative phrasing, Dutch may sometimes avoid this structure altogether, for example with an infinitive construction, but in your sentence dan dat is perfectly standard.

Because dat ik in de regen fiets is a subordinate clause.

In Dutch subordinate clauses, the conjugated verb usually goes to the end. That is why you get:

• dat ik in de regen fiets

and not:

• dat ik fiets in de regen

So the main clause is:

• Ik blijf liever thuis

and the subordinate comparison clause is:

• dan dat ik in de regen fiets

This is a very important Dutch word-order pattern.

Dutch often uses the simple present for this kind of general preference or immediate choice.

So ik fiets here does not have to mean only I am cycling right now. It can also express:

• a general possibility
• a usual action
• the action being compared with the preferred option

English often uses would rather, but Dutch does not need a direct equivalent in this sentence. The idea of preference is already carried by liever.

So:

• Ik blijf liever thuis dan dat ik in de regen fiets

  is a normal Dutch way to express I’d rather stay home than cycle in the rain.

Thuis is an adverb, not a noun.

It means at home or home, depending on the context. That is why there is no article before it.

Compare:

• Ik ben thuis. = I am at home.
• Ik blijf thuis. = I stay home / I stay at home.

English learners sometimes expect something like in huis or naar huis, but thuis is the usual word when talking about being or staying at home.

Yes, both are possible, but they are not exactly the same.

• in de regen fietsen = cycle in the rain
• door de regen fietsen = cycle through the rain

In de regen is the more direct match for the English idea of being out while it is raining.
Door de regen can sound a little more vivid, as if you are going through rainy conditions.

So your sentence is completely natural as it stands.

Yes. Dutch has several natural ways to express the same idea. For example:

• Ik blijf liever thuis dan in de regen te fietsen.
• Ik blijf liever thuis dan dat ik door de regen fiets.
• Ik fiets liever niet in de regen, dus ik blijf thuis.

The original sentence is good Dutch, but learners should know that Dutch often allows multiple comparison structures. The version with dan dat is especially useful because it lets you compare two full clauses clearly.

In this sentence, yes: Ik blijf liever thuis is the normal order.

Liever usually comes before the part it modifies, and here it modifies the whole idea of thuis blijven. So the standard word order is:

• Ik blijf liever thuis

If you move things around, the sentence may become marked, less natural, or change emphasis. For learners, it is best to keep liever in this position.

Yes, that is a very good way to understand the structure.

The sentence breaks down like this:

• Ik blijf liever thuis = I would rather stay home
• dan dat ik in de regen fiets = than cycle in the rain

So the overall pattern is:

• liever + option A + dan dat + option B

That is a very useful Dutch pattern to learn for expressing preferences between actions.