Ablam akşam çay hazırlarken ben de sofrayı kuruyorum.

Because ablam means my older sister.

• abla = older sister
• ablam = my older sister

The -m ending is a possessive suffix meaning my. With family words in Turkish, it is very common to use the possessed form:

• annem = my mother
• babam = my father
• ablam = my older sister

You usually do not need to add benim here, because the -m already shows possession.

Hazırlarken contains the ending -ken, which means while or when.

So:

• hazırlamak = to prepare
• hazırlarken = while preparing

In this sentence, ablam akşam çay hazırlarken means while my older sister is preparing tea in the evening.

This -ken form creates a time/background clause. It tells you what is happening at the same time as the main action.

It comes from the verb hazırlamak.

A simple way to think of it is:

• hazırla- = prepare
• -rken / -arken / -erken = while doing

So:

• hazırla + rken → hazırlarken

Learners often notice that this looks a bit compressed, and that is normal. You do not need to break it down too mechanically at first; the important point is that verb + -ken gives the meaning while doing that action.

Other examples:

• gelirken = while coming
• okurken = while reading
• yaparken = while doing/making

Yes, kuruyorum already tells you the subject is I, because the verb ending shows first person singular.

So why add ben?

Because here it adds contrast/emphasis:

• Ablam ... ben de ...
• My sister ... and I too ...

In Turkish, subject pronouns are often omitted, but they are added when you want to emphasize or contrast them.

Without ben, the sentence would still be grammatical in some contexts, but ben de makes the contrast clearer and more natural.

Here de means too / also / as well.

So ben de = I too / I also.

It is written separately because this de is a separate particle, not a suffix.

Compare:

• ben de = I too
• evde = in the house

In evde, the -de is a case ending and must be attached. In ben de, de is the also/too word, so it is separate.

Because of vowel harmony, this word can appear as de or da:

• ben de
• o da

Because Turkish often uses time words by themselves as adverbs.

So akşam can mean:

• in the evening
• this evening
• tonight

depending on context.

English usually needs something like in or this, but Turkish often does not.

Other similar examples:

• sabah = in the morning
• bugün = today
• yarın = tomorrow

So akşam in this sentence is perfectly normal as a time expression.

This is about definite/specific direct objects in Turkish.

• çay hazırlamak = prepare tea / make tea
  This is a non-specific or more general object, so no accusative is used.
• sofrayı kurmak = set the table
  Here sofrayı is marked as a specific/definite object.

A useful beginner rule is:

• bare object = non-specific/general
• accusative-marked object = specific/definite

So:

• çay hazırlıyor = preparing tea
• çayı hazırlıyor = preparing the tea

In your sentence, çay is just tea in a general sense, while sofrayı refers to the specific table setting being prepared.

Yes, more or less. Sofra kurmak is the normal Turkish expression for setting the table.

A few notes:

• sofra is not only the physical table itself
• it can also refer to the meal setting, place setting, or eating setup

So sofrayı kurmak means to prepare the table for a meal: plates, cutlery, bread, glasses, and so on.

It is an idiomatic, very common expression, so it is best learned as a chunk:

• sofra kurmak = to set the table

Because kuruyorum is the present continuous form, and it matches the idea of an action happening right now or in an ongoing scene.

• kuruyorum = I am setting
• kurarım = I set / I usually set / I will set in some contexts

Since the sentence describes two actions happening at the same time, the ongoing form is the natural choice:

• Ablam ... hazırlarken = while my sister is preparing...
• ben de ... kuruyorum = I am also setting...

If you used kurarım, it would sound more habitual or general, not as clearly part of the same unfolding moment.

Not completely, but the given order is very natural.

The basic structure is:

• Ablam akşam çay hazırlarken = background/time clause
• ben de sofrayı kuruyorum = main clause

Turkish often puts the -ken clause before the main clause, especially when setting the scene.

Also, Turkish is generally an SOV language, so the object usually comes before the verb:

• sofrayı kuruyorum
• object + verb

You can move elements around for emphasis, but that changes focus more than meaning. The original sentence sounds smooth and standard.

Usually it shows that one action is happening during another, but it does not always mean perfectly simultaneous in a mathematical sense.

In this sentence, it gives the idea of an overlapping scene:

• my sister is preparing tea
• during that time, I am also setting the table

So the feeling is clearly simultaneous background + main action.

In many everyday sentences, -ken works very much like English while.