لولا المدرب الشخصي لما اختار صديقي الدراجة الثابتة.

In this sentence, لولا introduces a counterfactual condition. It means something like if not for or were it not for.

So the structure is saying: because of the personal trainer, the result happened; without that person, the result would not have happened.

After لولا, Arabic often uses a noun phrase instead of a full clause.

So لولا المدرب الشخصي literally means something like:

• if not for the personal trainer
• or more fully, if the personal trainer had not been there / involved

Arabic leaves that idea understood rather than stating a separate verb.

A more grammar-heavy explanation is that the noun after لولا is followed by an omitted predicate that is understood from context.

Because after لولا in this kind of structure, the noun is normally treated as nominative.

So if the sentence were fully vowelled, you would get:

لولا المدربُ الشخصيُّ

not المدربَ الشخصيَّ.

This is one of those patterns you mostly learn as a set expression: لولا + noun (nominative).

No. Here it is not لَمّا in the sense of not yet or when.

In this sentence, لما is best understood as لَ + ما:

• لَ = the lām used in the result clause after لولا
• ما = negation

Together, لما اختار gives the sense of would not have chosen.

So this لما is part of the counterfactual structure, not the separate word لَمّا.

Because Arabic commonly uses the past tense form in unreal or counterfactual statements.

So even though English uses would have chosen, Arabic says:

لولا ... لما اختار

with the past form اختار.

This is very normal in Arabic conditional style. The past form here does not simply mean a plain past event; it is part of the counterfactual pattern.

Because Arabic often prefers verb-first word order in verbal sentences.

So:

اختار صديقي الدراجة الثابتة

is a normal verbal sentence:

• اختار = chose
• صديقي = my friend
• الدراجة الثابتة = the stationary bike

You could also put the subject first for emphasis or a slightly different feel, but the verb-first order here is very natural in MSA.

صديقي is:

• صديق = friend
• ـي = my

So it means my friend.

In this sentence, it is the subject of اختار.

It is nominative in function, but because it ends with ياء المتكلم (my), the normal case vowel is not clearly shown. Traditional grammar says the nominative marking is estimated rather than pronounced normally.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• المدرب الشخصي = the personal trainer
• الدراجة الثابتة = the stationary bike

This is the normal Arabic order:

• noun first
• adjective second

Also, the adjective must agree with the noun in:

• definiteness
• gender
• number
• case

That is why both words in each phrase have الـ.

Because دراجة is a feminine noun, so its adjective must also be feminine.

So:

• دراجة → feminine
• ثابتة → feminine adjective to match it

This is standard adjective agreement in Arabic.

Also, الدراجة الثابتة literally means the fixed/stationary bicycle, which is the normal Arabic way to express stationary bike or exercise bike.

Because ordinary Arabic writing usually leaves out short vowels and most case endings.

So the sentence as written is unvowelled:

لولا المدرب الشخصي لما اختار صديقي الدراجة الثابتة

But if fully vowelled, it would look something like:

لَوْلَا الْمُدَرِّبُ الشَّخْصِيُّ لَمَا اخْتَارَ صَدِيقِي الدَّرَّاجَةَ الثَّابِتَةَ

Those endings show the grammar more clearly, but in normal texts they are usually omitted.

Yes. Both begin with sun letters, so the ل of الـ is not pronounced separately.

So you say:

• الشخصي → ash-shakhṣī
• الثابتة → ath-thābitah

But in المدرب, the م is a moon letter, so the l is pronounced:

• المدرب → al-mudarrib

A careful reading of the whole sentence would be approximately:

lawlā al-mudarrib ash-shakhṣī lamā ikhtāra ṣadīqī ad-darrājata ath-thābitah

In pause, the final case vowels are often not pronounced.