Capital letters are not really an aspect of punctuation, but it is convenient to deal with them here. The rules for using them are mostly very simple.
(a) The first word of a sentence, or of a fragment, begins with a capital letter:
The bumbling wizard Rincewind is Pratchett's most popular character.
Will anyone now alive live to see a colony on the moon? Probably not.
Distressingly few pupils can locate Iraq or Japan on a map of the world.
(b) The names of the days of the week, and of the months of the year, are written with a capital letter:
Next Sunday France will hold a general election.
Mozart was born on 27 January, 1756.
Football practice takes place on Wednesdays and Fridays.
However, the names of seasons are not written with a capital:
Like cricket, baseball is played in the summer.
Do not write *"... in the Summer".
(c) The names of languages are always written with a capital letter. Be careful about this; it's a very common mistake.
Juliet speaks English, French, Italian and Portuguese.
I need to work on my Spanish irregular verbs.
Among the major languages of India are Hindi, Gujarati and Tamil.
These days, few students study Latin and Greek.
According to the calendar, autumn comes in September. In Central Russia, September is called the "thoughtful month". Days are quiet, the air is clear, the horizon seems to have moved away, revealing the beauty of autumn nature. With trees, even in windless hours, fly yellow leaves. Nature seems to be thinking in anticipation of big changes…
But this month still combines the signs of summer and autumn. When it's warm, you forget that summer has passed. And the wind will blow, the rains will pour, and it seems that there will always be cold, bad weather. The sun is showing less and less, the wind is getting colder. Clouds cover the sky. Autumn rains begin. Sun waiting as rewards, but in the morning looked out the window, you see a small gray rain