The verb देना (“to give”) is used in a common idiom which means “to allow/let someone/something to do something”.
Form
The oblique masculine singular infinitive of a main verb is followed by an inflected form of देना:
[oblique masculine singular form of the main verb] [inflected form of देना]
Examples
मेरी बहिन ने मुझे अपनी कंप्यूटर का इस्तेमाल करने दिया था – “My sister let me use her computer”
मेरा दोस्त मुझे अपनी गाड़ी चलाने देनेवाले है – “My friend is going to let me drive his car”
मेरी माँ मुझे वहां पर नहीं जाने देती है – “My mom doesn’t let me go over there”
वह हमें गलियां में नहीं खेलने देता है – “He doesn’t let us play in the alleyways”
Notes
Several grammatical points should be observed.
ने and Ergativity
देना is a transitive verb, and requires ने when it appears in its perfect/perfective transitive forms.
मेरी माँ ने उसको बाहर जाने नहीं दिया
In this instance, the subject was “blocked” by ने, and the object (उसको) was marked with को, so the verb defaulted to the masculine singular form.
Order of Negative Particles
Negative particles (नहीं, न, मत) may either precede or succeed the oblique infinitive.
With नहीं
हमें बच्चों को सड़क पर नहीं खेलने देना चाहिए – “We shouldn’t let the children play on the streets”
OR
हमें बच्चों को सड़क पर खेलने नहीं देना चाहिए – “We shouldn’t let the children play on the streets”
With मत
बच्चों को बाहर मत जाने दो – “Don’t let the children go outside”
OR
बच्चों को बाहर जाने मत दो – “Don’t let the children go outside”
With न
वह शायद तुम्हें न जाने दे – “He might not let you go”
वह शायद तुम्हें जाने न दे – “He might not let you go”
Common Expressions
This idiom is used in several common stereotypical expressions:
रहने दो – “Let it be” / “Leave it alone”
जाने दो – “Let it go” / “Forget about it”
With Inanimate Objects
This idiom, like “letting” in English, can be used with inanimate objects too:
खिड़की खुली रहने दो – “Leave the window open” / “Let the window remain open”
उसने एक घंटे तक खाना पकने दिया – “He let the food cook for one hour”
Similar Idioms
The words इजाज़त and आज्ञा can be used in a formal idiom to express permission. Both words are feminine nouns. The form of the idiom is as follows:
[oblique infinitive of verb] की [इजाज़त / आज्ञा] [form of देना]
This idiom may only be used with personal objects (not with inanimate objects), just as in English one would not say “He permitted the food to cook for one hour”. Instead, the oblique infinitive + देना idiom is used with inanimate objects.
मुझे जाने की आज्ञा दीजिये – “Please permit me to go” / “Please give me permission to go”