Learn Arabic (Modern Standard): لولا إرشادك، لفشلت في المشروع. - If not for your guidance, I would have failed the project.

Even though لولا translates to 'if not for', it is a conditional particle, not a preposition. Therefore, the noun immediately following it must be in the nominative case, meaning it takes a damma. If read aloud with full vowels, it is pronounced irshāduka, not irshādika.

Why is there a لـ attached to the beginning of فشلت?

The prefix لَـ (la-) is the result particle. When you use a hypothetical condition like لولا (if not for) or لو (if), the result clause often starts with this لَـ to clearly link the consequence to the condition. It helps give the meaning of 'then surely' or 'would have' in English.

Why does the result clause use the past tense verb فشلت instead of a conditional or future verb?

In Arabic, hypothetical sentences introduced by لولا or لو almost always use the past tense in the result clause. Because the condition itself is hypothetical, using the past tense locks in what the definite result would have been.

Why is the preposition في used here when the English translation just says 'failed the project'?

The Arabic verb فشل (to fail) does not take a direct object on its own. It requires the preposition في (in). So, instead of saying 'failed the project', Arabic literally says 'failed in the project' (فشلت في المشروع).