I wandered lonely as a cloud
That floats on high o'er vales and hills,
When all at once I saw a crowd,
A host, of golden daffodils;
Beside the lake, beneath the trees,
Fluttering and dancing in the breeze.

Continuous as the stars that shine
And twinkle on the Milky Way,
They stretched in a never-ending line
Along the margin of a bay;
Ten thousand saw I at a glance,
Tossing their heads in sprightly dance.

The waves beside them danced; but they
Out-did the sparkling waves in glee:
A poet could not but be gay,
In such a jocund company:
I gazed-and gazed-but little thought
What wealth the show to me had brought:

For oft, when on my couch I lie
In vacant or in pensive mood,
They flash upon that inward eye
Which is the bliss of solitude;
And then my heart with pleasure fills,
And dances with the daffodils.

William Wordsworth (1770-1850), was a great English poet. When many poets still wrote about great kings, queens and heroes in a grand style, Wordsworth focussed on nature, children and common people and used simple language to express his feelings. 

1. o'er - over
2. vales - valleys 
3. all at once - suddenly 
4. host - here, a large number
5. fluttering - moving in a light trembling manner
6. Milky Way - here, the flowers stretch continuously, like stars in the Milky Way galaxy
7. margin - edge
8. bay - a amall sea with land on three sides
9. at a glance - with a quick look
10. sprightly - lively, full of energy
11. out-did - did better than
12. glee - great delight
13. gay - joyful and happy (old English)
14. jocund - cheerful and light hearted
15. company - togetherness; friendship 
16. oft - often
17. couch - sofa
18. vacant - bored and with an empty mind
19. pensive - thoughtful, usually in a sad way
20. inward eye - the mind's eye or imagination
21. bliss of solitude - here, the thought of the daffodils brings happiness to the speaker when he is feeling lonely