يتكلم صديقي ببساطة.

In Modern Standard Arabic, a verb-first sentence is very common. So يتكلم صديقي is a normal way to say my friend speaks / is speaking.

You can also say صديقي يتكلم ببساطة. That version is also correct, but it puts a bit more focus on my friend.

So:

• يتكلم صديقي ببساطة = neutral, very standard
• صديقي يتكلم ببساطة = also correct, with more emphasis on the subject

يتكلم is a present/imperfect verb meaning he speaks, he is speaking, or sometimes he talks, depending on context.

It already tells you:

• the action: speak / talk
• the person: he
• the tense/aspect: present/imperfect

So Arabic does not need a separate word for he here.

Because the verb يتكلم already includes that information. The يـ at the beginning marks third person masculine singular in the imperfect verb, so he speaks is built into the verb.

If you add هو, it is usually for emphasis or contrast:

• هو يتكلم ببساطة = he speaks simply

But in a normal sentence, هو is not necessary.

صديقي is made from:

• صديق = friend
• ـي = my

So صديقي literally means friend-my, which is how Arabic expresses my friend.

This attached ـي is a possessive suffix. Arabic often uses suffixes instead of separate words like my, your, his, and so on.

Arabic usually expresses simple possession by attaching a suffix directly to the noun.

So the normal way to say my friend is:

• صديقي

Not:

• الصديق لي for this meaning

The structure noun + possessive suffix is the standard, natural way to say things like:

• كتابي = my book
• بيتي = my house
• صديقي = my friend

Because when a noun takes the ـي suffix meaning my, the case ending is not clearly visible in the usual written form.

In this sentence, صديقي is the subject, so grammatically it is nominative, but that nominative ending is not written out in a visible way here.

Also, everyday Arabic writing usually leaves out short vowels anyway, so many case details are hidden unless the text is fully vocalized.

ببساطة is made of two parts:

• بـ = with / in / by
• بساطة = simplicity

So literally it means something like with simplicity or in a simple way.

There are two b sounds because:

• the first ب is the preposition بـ
• the second ب is the first letter of بساطة

So بـ + بساطة = ببساطة

Yes. Even though it is literally a preposition plus a noun, in this sentence it functions like an adverbial expression.

So ببساطة means:

• simply
• plainly
• in a simple way

Arabic often uses phrases like this where English would use a single adverb.

A fully vowelled version is:

يَتَكَلَّمُ صَدِيقِي بِبَسَاطَةٍ

This shows:

• يَتَكَلَّمُ = the verb with its vowels
• صَدِيقِي = my friend
• بِبَسَاطَةٍ = simply / with simplicity

In careful reading, the last word has a genitive ending because it comes after the preposition بـ.

Yes. The Arabic imperfect often covers both ideas.

So يتكلم صديقي ببساطة could mean:

• My friend speaks simply
• My friend is speaking simply

Context tells you which one is meant. Arabic does not always separate simple present and present continuous as strictly as English does.

Yes, you could, but the nuance may change a little.

• يتكلم = speaks / talks
• يتحدث = speaks / talks, often a bit more formal, sometimes closer to addresses or discusses

For a simple sentence like this, يتكلم is very natural.

A simple pronunciation guide is:

yatakallamu ṣadīqī bibasāṭatin

If you are reading less formally or pausing at the end, the final case ending is often not fully pronounced.

A rough breakdown:

• يَتَكَلَّمُ = ya-ta-kal-la-mu
• صديقي = ṣa-dī-qī
• ببساطة = bi-ba-sā-ṭa(tin)

The doubled consonant in يتكلم comes from the shadda on ل.