I've been in India for almost 5 months now and my grasp of Hindi is nothing short of pathetic, in spite of this I seem to be getting by reasonably well. Admittedly I look like an absolute tool when trying to communicate but I can kind of get by in shops / restaurants / transport places. Below are my best guesses as to how I've managed to get anything done:
If the French colonised India instead of Britain I would be screwed. Thankfully (for me, in this one very particular circumstance) Great Britain was the tyrant to loot India and abuse it's people, not France. My countries disregard for other countries right to rule themselves means that there are many people in India that speak English. I heard that in other parts of India people actually use English over Hindi.
This technique is surprisingly effective. If I smile enough at people while pointing at things they'll generally try and attempt to find out what the hell I want. This may be because I'm smiling so they can see I'm trying to be nice, it may also be because they pity the simple gurning white fool that is waving his arms around in their store - whatever, it seems to work.
Namaste / Namascar = "Hello" : People put their hands together in a prayer symbol when they say hello here, I've started doing the same along with giving most people a big old smile as well because good manners never hurt anybody.
Kya = "What?" : There are only two situations where I really use this, in both situations I also employ a look of mild outrage:
1) If you can tell a group of people nearby are talking about you in Hindi, you can make them think you're onto them by turning to them and giving them a big ol' "Kyaaa?!?". I tend to use this tactic on drunk men at weddings (I've been to a lot of weddings...), a lot of the time it freaks them out, other times they just laugh at me.
2) When you are haggling down a price this is a good response to the first price offered.Kitna = "How Many?" : If you want to know how much something costs you can say "Kitna ruppees?", best followed by mild outrage and "Kya!?".
Bus = "Enough/Stop" : When people are pouring food onto your plate you can tell them when to stop with this word.
Tora = "A little" : Useful to control the amount of food someone is trying to put on your plate.
Chello = "Go" : It can be used like "lets go" but also you can say it as a way of saying goodbye.
Acha = "Good/Cool" : As words go, this is a fairly enjoyable word to say. Achaaaa.
Tikke = "Fine/Ok" : Kind of like Acha but as positive affirmations go this one is lower down relatively.
Ha = "Yes" :If someone starts speaking to you in Hindi and you want to pretend you know whats going on you can just say "Ha" during the periods where they stop speaking to make them think you understand whatever the hell they're saying. This strategy should be used with caution, I will demonstrate with a hypothetical example:
Hindi speaking stranger:" Āप डर्āर क्ōक्īन द्ūम्रप्āन करन्ē क्ē लि'ē मुम्ब'ī क्ī मलिन बस्टिय्ōṁ क्ē लि'ē म्ēर्ē स्āत ā'ō और अवैद र्ūप स्ē म्ōṭअरस्ā'इकिल डौṛअ ह्ōग्ī?" You:"Ha" You have now unwittingly agreed to smoke crack and then race through the slums of Mumbai on a motorcycle with this stranger. As you can see from this example, it is important for you to be cautious when agreeing to things that you do not actually know the meaning of
Nay ="No" : It's the word you should use if someone invites you to smoke crack and go motorcycle racing with them.
To conclude, I am pretty much fumbling my way through and it's working out ok. The biggest downside of not knowing much Hindi is the fact I can't have meaningful conversations with the vast majority of the Indian population including most of the adults in my village and that is a great shame as I'm missing out on making many new friends.