Sanskrit

ganga river is very oldest one.

गङ्गा नाम आपगा हिमवतो प्रभवति | भगीरथस्य तपसा प्रयत्नेन च सा स्वर्गात्भुवमानीता तमेव अनुसरन्ती पातालमेत्य त्रिपथगेति नाम्ना ख्याता लोके |

यमुना नाम निम्नगा पुनः हिमवतोद्भवा उत्तरापथं पावयन्ती गङ्गां प्रयागे संगच्छते | तत्र सरस्वती अन्तर्हिता गुह्यगामिनी वर्तते इति प्रतीतिः |

गोदावरी इतीयं सह्याद्रि पर्वतेषु जाता महाराष्ट्र देशं सिञ्चति, ततः आन्ध्रान प्रविश्य पुर्वसागरे लीयते |

नर्मदा नाम नदी पुनः पश्चिमपर्वतश्रेणिषूद्भूय आरभ्य सागरं प्रविशति |

सिन्धु: तु महानदी एव | पञ्च नदीनाम् एकत्वमाप्तवतीनाम् नदत्वं प्रत्याय्यते |

कावेरी नाम पुण्यनदी पुनः पश्चिमवर्तिषु पर्वतेषु जाता महर्षिणा अगस्त्येन भुवमानीता दक्षिणापथं पवित्रयति|

सप्त एताः नद्यः भारतं पवित्रयन्ति | ताश्च स्मर्यन्ते अनुदिनं पूजाकर्मणि अनेन श्लोकेनेत्यलं पल्लवितेन |

सन्ति च अन्या नद्यः शोण, मेघना, ब्रह्मपुत्रादयः परन्तु तासां पूज्यता नास्तीति मतेपि भारतीयानां नद्यः वन्द्या एव |

श्लो गङ्गे च यमुने चैव गोदावरी सरस्वती |

नर्मदे सिन्धु कावेरी जलेsस्मिन सन्निधिं कुरु

ahimsa (Sanskrit) : अहिंसा ahiMsaa: nonviolence; harmlessness; not injuring anything; non-injury.

Ahimsa is non-violence of any form against any living being. The idea is long standing principle of Hindu scriptures and is actively followed in India.

The idea was properly utilized in the freedom struggle against the British by Gandhiji. It is the most important principle of satyaagraha (सत्याग्रह).

satyaagraha सत्याग्रह(n): effort to discover, discern, obtain or apply the Truth [Gandhi ]

satyaagraha सत्याग्रह(verb): practice of non-violence

Please see the related link for more information on ahimsa and satyaagraha (also satyagraha)

उत्तिष्ठत जाग्रत प्राप्य वरान्निबोधत, क्षुरासन्न धारा निशिता दुरत्यद्दुर्गम पथ: तत् कवयो वदन्ति |

This is a sentence from the Katha- Upanishad[I will check this out and correct]. this is not a Hindi sentence. This is in Sanskrit and is from Scripture.

The meaning: Arise! Awake! Reach out for the Most Knowledgeable {In the Knowledge of The Ultimate} and know from them,(for) the Learned say that the Path to Realization is like walking on the Sword Blade, hence the path is most difficult to negotiate.

The first half of this statement has been translated by Swami Vivekananda as:

Arise! Awake! and Stop not till the goal is reached.

Since the Vedic Utterances have several tiered meanings it is possible to give a meaning of this sort, which the Learned Swamiji one of best Ambassadors of Sanatana Dharma, had used to inspire youth to be on the Path of Achieving One's Goals!

Sanskrit is the ancient most language written in Devnagri i.e. Hindi script.

There is no specific date available in History but is said to be learnt from Rishis by Shruti, meaning by hearing. Later that was adopted to write the Vedas and from the date Vedas are written and read, Sanskrit was recognised.

मातामही { मम्मो } matamah { mammo } = maternal grandmother

पितामही pitamah = paternal grandmother

मातामह matamaha = maternal grandfather

पितामह pitamaha = paternal grandfather