You've probably seen usage of the suffix "-wallah" such as the title of this post. It's used in English to mean "a person employed in a particular occupation or activity:" a taxi-wallah drives a cab; the shop-wallah runs the local grocery. You might even be aware that "-wallah" is of Indian origin. The suffix is an English borrowing from Hindi of the extremely useful suffix -वाला, which is rendered as "-wallah" in English. In this post I will use the more rigorous transliteration "-vaalaa".
In Hindi, -vaalaa does just what its borrowed cousin does in English, but it also does a lot more. There is no English equivalent, borrowed or otherwise, with the breadth of this fascinating little morpheme. So in this post, I will introduce you to some of the many and varied uses of -vaalaa.
First, adding -vaalaa to a noun carries the means: a person employed in an (understood) activity relating to the noun. In Hindi, the रिक्शे-वाला rikshe-vaalaa drives the rickshaw; the चाय-वाला chaay-vaalaa serves the tea (chai), the साड़ी-वाला saa.Dii-vaalaa sells sarees. That's the usage that has found its way into English.
-vaalaa can also be added to adjectives, to give a slightly emphatic or particularizing force, or to serve the purpose that the pronoun "one" serves in English:
क्या आप पीली-वाली साड़ी चाहती हैं? kyaa aap piilii-vaalii saa.Dii chaahatii hai.n? Do you want the yellow sari? (-vaalii is the feminine form of -vaalaa; Hindi has grammatical gender.)
नहीं, लाल-वाली । nahii.n, laal-vaalii. No, the red one.
In fact, -vaalaa can be added to pretty much any noun (including verbal nouns), adverb, or noun phrase, to give it adjectival (or even nominal) properties.
दोपहर dopahar, afternoon
-----> दोपहर-वाली गाड़ी dopahar-vaalii gaa.Dii, the afternoon train
पीले फूल piile phuul, yellow flowers
------> पीले फूल-वाली साड़ी - piile phuul-vaalii saa.Dii, the sari with the yellow flowers
हिंदी बोलना hi.ndii bolanaa, to speak Hindi
----> हिंदी बोलने-वाले hi.ndii bolane-vaale - Hindi speakers (-vaale is the masculine plural form of -vaalaa)
उपर upar, above; upstairs
-----> उपर-वाला कमरा upar-vaalaa kamaraa, the room upstairs, the upstairs room
------> उपर-वाला upar-vaalaa, the guy upstairs; i.e., God
Now things really start to get interesting. When used with an infinitive verb, -vaalaa turns the infinite into an adjective meaning "being about to" carry out the verb.
जाना jaanaa, to go
जाने-वाला jaane-vaalaa, about to go
-----> दिल्ली-वाली गाड़ी जाने-वाली है | dillii-vaalii gaa.Dii jaane-vaalii hai, the Delhi-bound train is about to leave.
होना honaa, to be, to become, to happen
होने-वाला hone-vaalaa, about to be, about to become, about to happen
-----> माँ होने-वाली maa.N hone-vaalii, about to become a mother; i.e., pregnant
-----> बारिश होने-वाली है । baarish hone-vaalii hai, rain is about to happen; i.e. it is about to rain
Finally, constructions with -vaalaa can be used in place of relative clauses like "the woman who works here." Hindi has a separate structure for creating relative clauses, but sometimes use of -vaalaa is simpler and more direct.
यहाँ काम करना yahaa.N kaam karanaa, to work here
यहाँ काम करने-वाली औरत मेरी बहन है । yahaa.N kaam karane-vaalii aurat merii bahan hai, the woman who works here is my sister.
Those are some common uses of -vaalaa, a very handy and versatile little morpheme - one of my favorite features of Hindi.