By my ouma en oupa se huis is dit altyd gesellig, selfs wanneer dit buite reën.

Not here. In this sentence, by means at or at the home/place of.

So:

• By my ouma en oupa se huis = At my grandma and grandpa’s house

This is very common in Afrikaans when talking about being at someone’s place:

• Ek is by my vriend. = I’m at my friend’s place.
• Ons eet by Ouma. = We’re eating at Grandma’s house.

So by often covers the idea that English expresses with at.

• ouma = grandma / grandmother
• oupa = grandpa / grandfather

They are very common everyday family words in Afrikaans.

Also, ou originally means old, but in these family words you should learn them as whole vocabulary items:

• ouma
• oupa

You do not need to translate them piece by piece in normal use.

se is a very common Afrikaans way to show possession.

Structure:

• possessor + se + thing possessed

So:

• my ouma en oupa se huis = my grandma and grandpa’s house

More examples:

• Jan se boek = Jan’s book
• die kind se skoene = the child’s shoes
• my suster se motor = my sister’s car

In your sentence, the whole phrase my ouma en oupa is the possessor, and huis is the thing owned.

So literally it is something like:

• my grandma and grandpa their house

But in natural English, we translate it as:

• my grandma and grandpa’s house

Because Afrikaans often puts a time or place phrase first for emphasis, and then the verb comes next.

This is a core Afrikaans word-order pattern:

• if something other than the subject comes first,
• the finite verb usually comes second,
• and the subject comes after it.

So:

• Dit is altyd gesellig by my ouma en oupa se huis. = It is always cozy at my grandparents’ house.

can become:

• By my ouma en oupa se huis is dit altyd gesellig. = At my grandparents’ house, it is always cozy.

This is similar to inversion in English after a fronted phrase, though Afrikaans uses it more systematically.

Here dit works like English it in sentences such as:

• It is nice here.
• It is cold today.
• It is cozy.

In is dit altyd gesellig, the dit does not refer to one specific object. It is more of an impersonal subject.

So:

• dit is gesellig = it is cozy / pleasant

Afrikaans uses dit in this kind of sentence just as English uses it.

gesellig is one of those words that has a broader feeling than one simple English translation.

Possible meanings include:

• cozy
• pleasant
• warm and welcoming
• sociable
• comfortable in a friendly way

In this sentence, gesellig suggests that the grandparents’ house feels warm, comfortable, and inviting.

So depending on context, you might translate it as:

• cozy
• pleasant
• homely
• nice and welcoming

A very natural translation here would be:

• At my grandma and grandpa’s house, it is always cozy...

altyd means always.

In this sentence:

• is dit altyd gesellig = it is always cozy

Its position is normal. In a simple statement, adverbs like altyd often come after the subject and before the descriptive word or further information.

Compare:

• Dit is altyd lekker hier. = It is always nice here.
• Hy is altyd laat. = He is always late.

So altyd is just the ordinary word for always.

selfs wanneer means even when.

Breakdown:

• selfs = even
• wanneer = when

So:

• selfs wanneer dit buite reën = even when it rains outside

This adds contrast: the house is cozy all the time, including during bad weather.

You may also see wanneer used in other sentences meaning when:

• Wanneer kom jy? = When are you coming?
• Ek lees wanneer ek tyd het. = I read when I have time.

wanneer dit buite reën is a normal and natural Afrikaans word order.

In the clause:

• dit = subject
• reën = verb
• buite = outside

Afrikaans often places adverbs like buite before the verb in this kind of clause:

• dit buite reën = it rains outside

You may sometimes hear slightly different word orders depending on style or emphasis, but the sentence as given is completely natural.

Also remember that after wanneer, Afrikaans uses normal subordinate-clause order patterns, so learners often need time to get used to how adverbs and verbs are arranged.

Yes. reën can be:

• a noun: rain
• a verb: to rain

In this sentence, it is a verb:

• dit buite reën = it rains outside

Examples:

• Die reën is swaar. = The rain is heavy. → noun
• Dit reën vandag. = It is raining today / It rains today. → verb

Afrikaans often uses the same form for related noun/verb pairs, so context tells you which one it is.

Yes, you could, but the feeling changes slightly.

• lekker = nice / pleasant / enjoyable
• gesellig = cozy / warm / convivial / welcoming

So:

• altyd lekker = more general: always nice there
• altyd gesellig = more specific: always cozy and warm in atmosphere

If you want to emphasize the emotional atmosphere of the home, gesellig is the better word.

Yes — three very useful patterns appear here:

1. Location first + verb second

   • By my ouma en oupa se huis is dit...
   • Fronting a place phrase causes inversion.

2. Possession with se

   • my ouma en oupa se huis
   • A very common Afrikaans possessive structure.

3. Impersonal dit

   • dit is gesellig
   • Just like English it is cozy

So this one sentence gives you several high-frequency Afrikaans structures that are worth remembering.