Compound verbs consist of two parts: a non-verbal word (like a noun) and a "light" verb (like کردن). To form the future tense, Farsi splits these components. The conjugated auxiliary verb (خواستن) sits exactly between the non-verbal part and the short infinitive of the light verb.
[Non-verbal part] + [Conjugated auxiliary] + [Short infinitive]
Let's look at the compound verb for "to test":
| to test | آزمایش کردنâzmâyesh kardan |
To say "we will test", take the non-verbal part (آزمایش), add the "we" form of the auxiliary (خواهیم), and finish with the short infinitive of the light verb (کرد).
| We will test the blood in the laboratory. | ما خون را در آزمایشگاه آزمایش خواهیم کرد.mâ khun râ dar âzmâyeshgâh âzmâyesh khâhim kard |
The auxiliary verb changes depending on the subject, while the light verb remains as the static short infinitive (کرد). Here is the "they" form:
| Scientists will test the new vaccine in the laboratory. | دانشمندان واکسن جدید را در آزمایشگاه آزمایش خواهند کرد.dâneshmandân vâksan-e jadid râ dar âzmâyeshgâh âzmâyesh khâhand kard. |
More Examples
This same rule applies to all compound verbs, such as درمان کردن (to treat / to cure) and تحقیق کردن (to research). Observe how the auxiliary verb steps into the middle of the compound:
| The scientists will cure this new disease. | دانشمندان این بیماری جدید را درمان خواهند کرد.dâneshmandân in bimâri-ye jadid râ darmân khâhand kard. |
| Will you treat the patient? | آیا بیمار را درمان خواهید کرد؟âyâ bimâr râ darmân khâhid kard? |
| I do not have time today, but tomorrow I will do research in the laboratory. | امروز وقت ندارم، ولی فردا در آزمایشگاه تحقیق خواهم کرد.emruz vaght nadâram, vali fardâ dar âzmâyeshgâh tahghigh khâham kard. |