Learn Hardcore Dutch: We kunnen de route andersom lopen als jij dat fijner vindt. - We can walk the route the other way around if you prefer that.

Main clause: Dutch is verb-second (V2). The finite verb (kunnen) comes in second position, and other verb(s) go to the end: We [kunnen] … [lopen].
Subordinate clause with als (“if/when”): the finite verb goes to the end: als jij dat fijner [vindt].

What exactly does andersom mean?

It means “the other way around,” “in the opposite direction/order.” It’s about reversing direction/order, not about walking backwards. For “backwards,” use achteruit. Synonyms: omgekeerd, in omgekeerde richting.

Where can andersom go in this sentence?

Most natural: just before the main verb phrase or after the object:

We kunnen de route andersom lopen. (best)
We kunnen andersom de route lopen. (possible, a bit marked)
We kunnen de route lopen, andersom. (only as an afterthought in speech) Keep andersom close to the verb phrase it modifies.

Is omlopen the same as andersom lopen?

No.

omlopen = to take a detour / walk around something.
andersom lopen = to do the same route but in the reverse direction/order.
Don’t confuse them.

Why de route and not het route?

Because route is a common-gender noun in Dutch, so it takes de.

singular: de route
plural: de routes
demonstratives: deze route, die route

Can I use wandelen instead of lopen here?

You can, but the idiomatic collocation is een route lopen for walking a route.

wandelen suggests leisurely strolling; it’s fine without a direct object or with terms like wandelroute.
With a route object, lopen is most neutral: de route (andersom) lopen.

Why is there dat in als jij dat fijner vindt? What does it refer to? Could I use het?

dat is a demonstrative pronoun referring back to the specific option just mentioned: doing the route in reverse. You can also say als jij het fijner vindt; het is more neutral, while dat points more clearly to “that option.” Both are idiomatic here.

Why is it spelled vindt with -dt? When do I write vind vs vindt?

Present tense of vinden:

ik vind
jij/je vindt; hij/zij/het vindt
In inversion (verb before subject): vind je …? (no -t after jij/je), but with u it stays vindt u …? In your sentence the subject (jij) precedes the verb, so it’s vindt.

Could I say liever instead of fijner?

Yes, and it’s often more idiomatic for preference:

We kunnen de route andersom lopen, als je dat liever wilt.
Or more directly: We lopen liever andersom. fijner = “more pleasant/nicer.” liever = “rather/prefer.” Both work; liever sounds very natural for choices.

Can I use wanneer or indien instead of als?

als covers both “if/when” in everyday speech and is best here.
wanneer focuses on time (“when”) and sounds odd for pure conditions in informal speech.
indien is formal (“if”) and is fine in formal writing but stiff in conversation.

Why jij and not je?

jij is the stressed/emphatic form; je is the unstressed/neutral form.

als jij dat fijner vindt emphasizes that it’s your preference in particular.
Neutral: als je dat fijner vindt (also very common).

How would the sentence look if the als-clause came first?

Als jij dat fijner vindt, kunnen we de route andersom lopen.
Note the comma, and the main clause keeps V2: kunnen we, not we kunnen.

How do you pronounce key words like route, andersom, kunnen, vindt?

route ≈ “ROO-tuh” (most common); some regions say “ROU-tuh.”
andersom ≈ “AHN-duhr-ZOM” (stress on the last syllable).
kunnen ≈ “KUH-nuhn” (u like the vowel in Dutch “bus”).
vindt sounds like “vint” (final -dt is pronounced as /t/).

Is kunnen here ability, permission, or a suggestion? Any other polite ways to phrase it?

It’s a polite suggestion/offer. Alternatives:

Zullen we de route andersom lopen? (Shall we…?)
We zouden de route andersom kunnen lopen. (We could…)

Are there good alternatives to andersom?

Yes:

omgekeerd
in omgekeerde richting
de andere kant op
For circular routes: tegen de klok in (“counterclockwise”) / met de klok mee (“clockwise”)

Can I omit de route and just say We kunnen andersom lopen?

Only if the route is clear from context; otherwise it’s vague (and could be misheard as “walk backwards”). With a specific route in mind, include de route for clarity.