Öğretmen konuyu sade bir biçimde açıklıyor.

It follows the common Turkish pattern Subject + Object + Adverbial phrase + Verb:

• Öğretmen = subject
• konuyu = direct object
• sade bir biçimde = adverbial phrase, describing how the action is done
• açıklıyor = verb

Turkish usually places the verb at the end, so this is a very typical word order.

Because konuyu has the accusative case ending, which marks a specific definite direct object.

• konu = topic
• konu-yu = the topic

The -y- is a buffer consonant. Turkish adds it when a vowel-final noun takes a vowel-initial suffix.

So:

• konu = topic
• konuyu = the topic

Here, the teacher is explaining a particular topic, not just any topic in general.

It tells you the object is specific or definite.

Compare:

• Öğretmen konu açıklıyor = unnatural or incomplete in most normal contexts
• Öğretmen bir konu açıklıyor = The teacher is explaining a topic
• Öğretmen konuyu açıklıyor = The teacher is explaining the topic

So -u / -ü / -ı / -i on a direct object often signals that the speaker has a particular object in mind.

Here sade means simple, plain, or clear.

So sade bir biçimde means something like:

• in a simple way
• in a plain way
• in a clear, uncomplicated manner

In this sentence, it describes how the teacher explains the topic.

Turkish often uses a noun phrase like ... bir biçimde or ... bir şekilde to mean in a ... way.

So:

• biçim = form, manner, way
• sade bir biçimde = in a simple way

This is a very natural way in Turkish to express manner. English sometimes does the same with phrases like in a simple way instead of just simply.

Here bir does not really mean the number one in a strong sense. It is part of a natural Turkish expression.

• bir biçimde = in a way / in a manner
• sade bir biçimde = in a simple way

So bir helps build the phrase, much like English a in in a simple way.

The ending -de is the locative case, which usually means in, at, or on. But in expressions like this, it helps create an adverbial meaning.

• biçim = manner, form
• biçimde = in a manner / in a way

So sade bir biçimde literally means something like in a simple manner.

It is -de, not -te, because biçim ends in the voiced consonant m, and the suffix matches that.

Açıklıyor is the present continuous or progressive form.

• açıklamak = to explain
• açıklıyor = is explaining / explains

In Turkish, this form can mean:

• an action happening right now
• a present action in progress
• sometimes even a regular or current activity, depending on context

So it may translate as either is explaining or explains, depending on the situation.

Because when a Turkish verb stem ends in a vowel and takes the progressive suffix -iyor / -ıyor / -uyor / -üyor, that final stem vowel usually drops.

So:

• açıkla-
  • -ıyor
    becomes
• açıklıyor

This happens with many verbs:

• başla- → başlıyor
• anla- → anlıyor
• bekle- → bekliyor

So açıklıyor is the normal correct form.

Yes. Turkish -yor often covers both ideas, depending on context.

So Öğretmen konuyu sade bir biçimde açıklıyor can mean:

• The teacher is explaining the topic in a simple way
• The teacher explains the topic in a simple way

If there is no extra context, both are possible.

Turkish does not have articles like English the and a/an in the same way.

So öğretmen can mean:

• teacher
• the teacher

The exact meaning comes from context.

Turkish can use bir for a/an, but it does not use a separate word for the.

Yes, Turkish word order is flexible, but the neutral order here is very natural.

This sentence gives information in a straightforward way:

• Öğretmen = who
• konuyu = what
• sade bir biçimde = how
• açıklıyor = action

You could move parts around for emphasis, but the verb usually stays near the end. For example:

• Konuyu öğretmen sade bir biçimde açıklıyor

This still means basically the same thing, but the emphasis changes. The original version is the most neutral and standard.

No, not in this sentence.

• sade = simple, plain
• sadece = only, just

So here:

• sade bir biçimde = in a simple way

It does not mean only in a way or anything like that. This is a very common confusion for learners, so it is good to notice the difference.