التليفون بيفصل في المكالمات.

Because ت is a sun letter. In Arabic, when الـ comes before a sun letter, the l sound of الـ assimilates to the next consonant.

So:

• ال + تليفون
• becomes pronounced roughly et-telefōn

You usually hear a doubled t sound, not an l sound.

A natural Egyptian pronunciation is roughly:

et-telefōn biyefṣal fil-makalmāt

A looser English-style approximation would be:

et-tele-FONE bi-YEF-sal fil-ma-kal-MAAT

A few notes:

• بيفصل = biyefṣal / biyefsal
• في المكالمات often runs together in speech as fil-makalmāt
• The ṣ sound in careful transliteration is an emphatic s, but many learners can start with a regular s-like sound

Here بيفصل means something like:

• disconnects
• cuts out
• drops
• shuts off

The basic root فصل has the idea of separating or disconnecting, but in everyday Egyptian it is often used for devices or connections that stop working properly.

So in this sentence, it is not about a literal physical separation. It means the phone connection is failing during calls.

In Egyptian Arabic, the prefix بـ on the verb usually marks the present / habitual / ongoing form.

So:

• يفصل on its own is not the normal plain present form in Egyptian conversation
• بيفصل means it disconnects, it keeps disconnecting, or it tends to disconnect

In this sentence, بيفصل suggests a repeated or general problem, like the phone cuts out during calls.

Because the verb itself already tells you the subject is he/it in the singular masculine form.

• بيفصل = it disconnects / he disconnects

Since التليفون is already stated, Arabic does not need an extra word like English it.

So the structure is simply:

• التليفون = the phone
• بيفصل = disconnects / cuts out

Because التليفون is treated as a masculine singular noun in Arabic.

So the verb appears in the matching masculine singular form:

• التليفون بيفصل

If the subject were a feminine noun, the verb form would change.

Literally, it is in the calls, but the natural meaning is:

• during calls
• on calls
• when I’m in calls

The preposition في often covers meanings like in, during, or while involved in something, depending on context.

So في المكالمات is a natural way to say during phone calls.

Not necessarily. In Arabic, a definite plural can be used in a general sense.

So في المكالمات can mean:

• during calls
• when making calls
• in phone conversations generally

It does not have to mean a specific known set of calls.

This is very normal in Arabic and often sounds more natural than trying to make it indefinite in English-like ways.

Yes. تليفون is very common in Egyptian Arabic.

A few related notes:

• تليفون = phone / telephone
• موبايل = mobile phone / cell phone
• هاتف = more formal or Modern Standard Arabic

So in everyday Egyptian speech, التليفون sounds very normal.

Yes, and the choice can slightly change the nuance.

• بيفصل often suggests disconnecting, dropping, or shutting off
• بيقطع often suggests cutting out, breaking up, or an interrupted connection

For bad call quality, many speakers might also use بيقطع.
For a dropped call or a phone that disconnects, بيفصل works very well.

So both can appear in phone-related complaints, but they are not always exactly identical.

You would usually say:

التليفون ما بيفصلش في المكالمات

That means:

• The phone doesn’t disconnect during calls
• The phone doesn’t cut out during calls

In Egyptian Arabic, present-tense negation is often:

• ما + verb + ش

So:

• بيفصل → ما بيفصلش

It sounds clearly Egyptian / colloquial because of the verb form بيفصل.

That بـ present marker is a strong sign of spoken Egyptian Arabic.

A more Modern Standard Arabic version might be something like:

• الهاتف ينقطع أثناء المكالمات

That sounds more formal.
The original sentence sounds like everyday Egyptian speech.

Usually in this context, it most naturally means the phone disconnects during calls or the call drops/cuts out.

But بيفصل can be used in other contexts for a device that switches off, freezes, or stops working.

So the exact nuance depends on context:

• with في المكالمات, most people will understand the problem happens during calls
• that usually points to call disconnection rather than the entire phone fully powering off