Mercimeği haşladıktan sonra çorbaya ekledim.

Two things are happening:

• mercimek is the dictionary form.
• In the sentence, it becomes mercimeği because it takes the accusative ending, used for a specific direct object.

Also, the final k changes to ğ before a vowel in many Turkish words:

• mercimek → mercimeği

So this form means something like the lentils / the lentil as a specific thing being acted on.

It marks the noun as a definite/specific direct object.

Compare the idea:

• mercimek ekledim = I added lentils / some lentils
• mercimeği ekledim = I added the lentils / the specific lentils

In this sentence, the speaker is talking about a particular lentil ingredient already understood in the situation, so mercimeği is natural.

It means after boiling or more literally after having boiled.

It breaks down like this:

• haşla- = boil
• -dıktan = after doing
• sonra = after

So:

• haşladıktan sonra = after boiling

This is a very common Turkish pattern:

• geldikten sonra = after coming
• yemek yedikten sonra = after eating
• bitirdikten sonra = after finishing

Because Turkish often leaves the subject unstated when it is already clear.

Here, the main verb is ekledim:

• ekle- = add
• -di- = past
• -m = I

So ekledim already means I added.

Because of that, haşladıktan sonra is normally understood as after I boiled it/them. Turkish does not need to repeat ben unless the speaker wants emphasis.

Normally, the subject of haşladıktan sonra is understood to be the same subject as the main verb unless something else is stated.

So in this sentence:

• ekledim = I added
• therefore haşladıktan sonra is naturally understood as after I boiled

This same-subject interpretation is very common with this structure.

Because eklemek usually works like this:

• X-i Y-ye eklemek = to add X to Y

So here:

• mercimeği = the thing being added
• çorbaya = to the soup

The ending -ya is the dative ending, showing the destination or target of the action.

• çorba → çorbaya

The extra y appears because Turkish often uses a buffer consonant between two vowels.

Ekledim breaks down as:

• ekle- = add
• -di = past tense
• -m = first person singular

So ekledim means I added.

This is why Turkish often does not need a separate subject pronoun.

Turkish often does not repeat a pronoun if the object is already clear from context.

In English, you might say:

• After boiling the lentils, I added them to the soup.

In Turkish, once mercimeği has already been mentioned, the repeated object can simply be left understood. That is very natural.

So the sentence does not need an extra word for them.

In Turkish, mercimek is often treated like a mass noun, similar to words like rice in English.

So mercimeği can refer to:

• lentils in general as an ingredient
• the lentils being used in this recipe

Even though English often translates it as the lentils, Turkish does not need an explicit plural here.

If someone wanted to make the plural very explicit, they could say mercimekleri, but that is not necessary in this kind of cooking sentence.

Yes. It is very normal Turkish word order.

A few points:

• The main verb often comes at the end: ekledim
• Time expressions like haşladıktan sonra commonly come before the main verb
• The object mercimeği can be placed early in the sentence

So this sentence is natural. Turkish word order is also somewhat flexible, and changing the order can shift emphasis. For example, Haşladıktan sonra mercimeği çorbaya ekledim is also possible, but the focus feels slightly different.