لما بفكر في الجملة كويس، بختار الكلمة الصح.

Here لما means when.

It introduces a time-related idea, like when/whenever in English:

• لما بفكر... = when I think...

In Egyptian Arabic, لما is very common in everyday speech for this kind of sentence.

The بـ prefix is a very common Egyptian Arabic marker for the present/habitual.

So:

• بفكر = I think / I am thinking (depending on context)
• بختار = I choose / I am choosing

In this sentence, the meaning is more habitual/general:

• When I think carefully about the sentence, I choose the right word.

This is different from some other forms you may see in Arabic, especially in MSA.

Because the verb itself already shows the subject.

• بفكر = I think
• بختار = I choose

The أ / b-... pattern in the verb tells you the subject is I.
So Egyptian Arabic often leaves out the pronoun أنا unless it is needed for emphasis.

You could say:

• لما أنا بفكر...

but it is usually unnecessary.

Because فكر في is the normal expression for think about in Arabic.

So:

• فكر في حاجة = think about something

That means:

• بفكر في الجملة = I think about the sentence

English also uses a preposition here: think about the sentence.
Egyptian Arabic uses في in this structure.

كويس here means something like well, carefully, or properly, depending on context.

So:

• بفكر في الجملة كويس = I think about the sentence carefully / well

Even though كويس often means good as an adjective, in Egyptian Arabic it is also very commonly used in an adverb-like way.

Examples:

• أنا كويس = I’m fine
• اسمع كويس = listen carefully
• فكر كويس = think carefully

Because it is modifying the whole action بفكر في الجملة rather than directly describing the noun الجملة.

So the structure is:

• لما = when
• بفكر في الجملة = I think about the sentence
• كويس = carefully / well
• بختار الكلمة الصح = I choose the right word

Putting كويس after the phrase is very natural in Egyptian Arabic.

الصح means the correct one or the right one.

So:

• الكلمة الصح = the right word / the correct word

In Egyptian Arabic, صح is very commonly used in everyday speech to mean correct/right.

Compare:

• ده صح = this is correct
• الإجابة الصح = the correct answer
• الكلمة الصح = the right word

Because this is Egyptian Arabic, not Modern Standard Arabic.

In MSA, you might expect something like:

• الكلمة الصحيحة

But in Egyptian, people very naturally say:

• الكلمة الصح

This is a very common colloquial pattern: a simple spoken adjective comes after the noun.

So this sentence sounds natural and everyday.

Here الجملة most naturally means the sentence.

In other contexts, جملة can also mean things like:

• sentence in grammar/language
• phrase
• sometimes whole/entirety in certain expressions

But in this sentence, it clearly refers to a linguistic sentence.

Starting with لما بفكر في الجملة كويس puts the condition/time frame first:

• When I think carefully about the sentence, I choose the right word.

This is very natural in both English and Arabic.

You could also hear similar sentences with the main idea first in conversation, but this order is clear and common.

A very literal breakdown would be:

• لما = when
• بفكر = I think
• في الجملة = about the sentence
• كويس = well/carefully
• بختار = I choose
• الكلمة = the word
• الصح = the right/correct

So, literally:

• When I think about the sentence well, I choose the right word.

That helps you see the structure, even if the smoother English translation would be more natural.

A simple pronunciation guide is:

• lamma bafakkar fil-gomla kwayyis, bakhtar il-kelma s-saḥ

A few notes:

• لما = lamma
• بفكر is often heard close to bafakkar
• الجملة in Egyptian is usually el-gomla or il-gomla, not the MSA-style al-jumla
• كويس is often pronounced kwayyis
• الصح has an emphatic ṣ/ṣaḥ sound, often written saḥ or ṣaḥ

Different transliterations are possible, but that pronunciation is a good guide.

Sometimes, yes, but لما is one of the most natural choices here.

Other words may exist depending on the exact meaning or level of formality, but for everyday Egyptian Arabic:

• لما بفكر... sounds very normal.

So if you are learning spoken Egyptian, لما is a very useful and safe choice for this kind of sentence.