Bhagvad Gita VI:34

This is one of my favourite verses in the Gita. Arjuna speaks for most human beings in the struggle to control the mind. Swami Vivekananda once said the mind was like a monkey, a drunk monkey... that has been stung by a scorpion... Can't agree more!! Anyhow. This is about translation, so here it is:

चंचलं ही मनः कृष्ण

प्रमाथि बलवद् दृढम्

तस्याहं निग्रहं मन्ये

वायोरिव सुदुष्करम्

The mind indeed is unstable, Krishna, turbulent, powerful and obstinate;

Controlling it is as difficult as (controlling) the wind.

चंचलं - unsteady, unstable (neut., nominative, singular) Notice the म् becomes an anusvara before the ह् of ही

ही - indeed, verily (avyaya)

मनः - mind (neut., nom., sing) 

कृष्ण - O Krishna (vocative)

Notice that both the nouns are in the nominative. And the 'asti' [is] is assumed. This is an example of a nominative sentence.

प्रमाथि - troubling, harassing  (neut., nom., sing)

बलवद् - powerful (neut., nom., sing) the 't' of balavat has become a 'd' before दृढम्

दृढम् - fixed, unyielding (neut., nom., sing)

Like चंचलं in the previous sentence, these are three neuter nouns being used as adjectives to describe the mind. It is this .. and this.. and this... etc.

तस्याहं निग्रहं मन्ये

वायोरिव सुदुष्करम्

(अहं मन्ये तस्य निग्रहं वायोरिव  सुदुष्करम् [अस्ति])

(lit. I think its control is as difficult as [of] the wind)

One of the things you will have to get used to is that the word order is often not what you would find in prose - this is to fit not just the rhyme scheme, but also the meter. Therefore it is absolutely critical that you pay keen attention to the endings to unravel the meaning of each word and the sentence. This one is easy. But they get really complex. 

तस्याहं = तस्य + अहम् Where the 'a' in the य is in sandhi with the 'a' of अहम् to make an आ

 तस्य - its, of it, of this (neut., genitive singular) 

अहम् - I

निग्रहं - restraining, suppressing (masc., accusative., sing ni√grah)  

मन्ये - (I) think (1st person, sing., present, ĀP, √man)

वायोरिव = वायोः + इव

वायोः  - of the wind (masc., genitive, sing.)

इव - like (avyaya)

सुदुष्करम् - (neut., accusative, singular) 

This is an interesting word, juxtaposing  'su' and 'du' which are opposites. In such cases, the 'su' is used to stress the 'du' (negative aspect/difficulty) of the word.