Hafta sonu büyükannemi ziyaret ettik.

Yes. Hafta means week and sonu means its end / the end. Together, hafta sonu is the normal expression for the weekend.

So in this sentence, Hafta sonu means on the weekend or at the weekend.

Turkish often uses time expressions without a preposition.

So:

• Hafta sonu büyükannemi ziyaret ettik. = We visited my grandmother on the weekend.
• Dün geldim. = I came yesterday.
• Pazartesi gidiyoruz. = We are going on Monday.

English usually needs on, at, or in, but Turkish often does not.

It breaks down like this:

• büyükanne = grandmother
• büyükannem = my grandmother
• büyükannemi = my grandmother as the direct object of the verb

So the word contains both:

• the possessive idea my
• the object marking needed in this sentence

That -i is the accusative ending, which marks a specific direct object.

In this sentence, the speaker means a particular person: my grandmother. Because the object is specific, Turkish uses the accusative.

So:

• büyükannem = my grandmother
• büyükannemi = my grandmother as the thing/person being visited

A useful rule: possessed nouns like my grandmother, your house, our teacher are normally definite/specific, so if they are direct objects, they usually take the accusative.

Ziyaret etmek is a very common Turkish compound verb meaning to visit.

It is made of:

• ziyaret = visit / visitation (a noun)
• etmek = to do / to make

Together:

• ziyaret etmek = to visit

Turkish has many verbs like this, where a noun combines with etmek, yapmak, or olmak.

So ziyaret ettik simply means we visited.

Ettik comes from etmek.

It can be broken down as:

• et- = verb stem
• -ti = past tense
• -k = we

So:

• ettik = we did
• in ziyaret ettik, it means we visited

The double tt appears because the stem ends in t and the past tense suffix also begins with a t sound here.

It is built into the verb ettik.

The ending -k shows we.

So Turkish does not need a separate subject pronoun here. You could say Biz hafta sonu büyükannemi ziyaret ettik, but biz is usually unnecessary unless you want emphasis or contrast.

This is very common in Turkish:

• geldim = I came
• geldin = you came
• geldik = we came

Because Turkish normally prefers Subject-Object-Verb word order, and time expressions often come near the beginning.

So the structure here is roughly:

• Hafta sonu = time
• büyükannemi = object
• ziyaret ettik = verb

This end-of-sentence verb position is very typical in Turkish.

Yes, Turkish word order is flexible, but different orders change the focus or emphasis.

For example:

• Hafta sonu büyükannemi ziyaret ettik.
  Neutral, natural order.

• Büyükannemi hafta sonu ziyaret ettik.
  Slightly more focus on my grandmother.

• Hafta sonu ziyaret ettik büyükannemi.
  Possible in speech or for special emphasis, but less neutral.

In ordinary textbook Turkish, keeping the verb at the end is the safest choice.

Büyükanne is the general word for grandmother.

If Turkish speakers want to be more specific, they often use:

• anneanne = maternal grandmother
• babaanne = paternal grandmother

So büyükannemi just means my grandmother, without saying which side of the family, unless the context makes it clear.