In spoken Persian, the prepositions may be connected to the objective enclitics, in which case, az ‘of, from,’ tu ‘in, inside’ (instead of the formal dar), and some others stay constant; but be takes an epenthesis as beh and bā becomes bāha or bāhā, to avoid hiatus; as follows:

With prepositions with a terminal /u/, namely tu ‘in, inside’, ru ‘on, over, above, on top of’, and polysyllabic prepositions, namely bālā ‘on, over, above, on top of’, etc., because of the final long vowel, the enclitics do not have an initial vowel and the following enclitics are used:

For example:

The preposition همراه hamrāh ‘along with’ loses its final h and, then, takes the same set of enclitics:

In spoken Persian در dar ‘in, inside’ is hardly ever used; most usages are in compounds such as درجا dar-jā ‘on the spot’, as in درجا مرد dar-jā mord ‘he/she/it died right there and then/right away/on the spot’.

Normally در dar is suppleted by تو tu, which may optionally take the ezāfe construction; for example, تو خونه tu xune or توی خونه tu-ye xune ‘in the house’.

In the case of تو tu, however, it is not used as often as درdar is used in written Persian. For instance, instead of saying پدرم توی خونه س pedaram tu (ye) xunas ‘my father is at home’, it is very normal to say پدرم خونه س pedaram xunas (which, by the way, could literally mean my father is a house). If occasionally پدرم توی خونه س pedaram tu (ye) xunas is used; it (often) means ‘my father is inside the house’ (and, for instance, he is not in the garden, backyard, or elsewhere around the house).

The post-vocalic ezāfe [-ye] (which is used formally) may optionally be dropped after /u/, as in رو ru ~ روی ru-ye ‘on, on top of’, پلو pa:lu ~ پلوی pa:luye ( پهلو~پهلوی pahlu ~ pahlu-ye) ‘next to’; for example, رو یخچال ru yaxcāl ‘on the fridge’, instead of روی یخچال ru-ye yaxcāl; او پهلو من نشسته u pahlu man nešaste ‘he/she is sitting next to me’ (instead of …پهلوی من pahlu-ye man…).

After /ā/ we may variably get [-ye] or [-y]; for example, [ بالای یخچال bālāye yaxcāl or bālāy yaxcāl ‘on the fridge’ (and variably, in the Tehrani dialect, بالا یخچال bālā yaxcāl, without the ezāfe construction).

The preposition برای barāye is hardly ever used in Tehran, instead in the Tehrani dialect more often واسه vāse, واسه ی vāseye, and, occasionally, برا barā (without the ezāfe construction) are used, as in برا من barā man, واسه من vāse man or vāseye man ‘for me’. In recent years, vāse is more and more borrowed from Tehrani and used in some other dialects as well, especially under the influence of the media. With vāse (with the terminal [-e]) see above.

For example:

If instead of vāse, barā is used, then the enclitics are the same set used after a long [-ā-]:

For example:

In words with بر bar ‘above, upon’ and در dar ‘in, inside’ as a member of a prepositional compound, the بر and در are normally dropped. For instance, between بین beyn and دربین dar beyn ‘among; between’, the latter is almost never used in colloquial Persian (Although it must also be mentioned that instead of (dar) beyn, میون miyun (from the formal میان) is more common, anyway.) Quite the same, درپیش dar piše ‘before, in front of’ is always پیش piše; بر سر bar sare ‘at the tip of, on top of’ is always سر sare, etc. Notice that all of these prepositions take the ezāfe construction.

The preposition ﺒ be ‘to, towards’ is very rarely—and in a very specific situation—used. For instance, in dealing with direction towards a location, it is almost never used; for example: می خوام برم خونه mixām beram xune ‘I want to go home’, hardly ever می خوام برم به خونه mxām beram be xune.

Normally in many instances spoken Persian has an inclination towards the Arabic loanwords as opposed to Persian words, as in متشکرم motešakkeram (secondarily متشکرم motšakkeram) and ممنونم mamnunam vs. سپاسگزارم sepāsgozāram ‘thank you!’. (In Tehrani, even the French loanword merci is used more often.)

Accordingly, in the case of prepositions, normally the Perso-Arabic بعد از بعد از ba’d (az) is used instead of Persian پس از پس از pas (az) ‘after(wards)’; and, although پیش پیش piš is used profusely, قبل از is more common than پیش از پیش از piš az ‘before.’

Post-consonantal:

Prepositions mostly remain the same as the written forms, such as be ‘to, at’ az ‘from, of’ etc.