Practise using capital letters for names, places and people and to begin direct speech. Proper nouns are always capitalised in English. People's names, including first names and surnames, titles, such as Her Majesty, Mrs, or Mr, place names, such as Northern Ireland, Manchester, or Piccadilly Circus, are all capitalised. Book, film and song titles are capitalised. Even the names of some of your classes, like English Literature, are probably capitalised!
When you are adding dialogue to a sentence, you will also need to use a capital letter for the first word in the dialogue, even though that is not the first word of your sentence. It can help to remember that it is the first word of your character's sentence, however! This, for example, would be correct: Susan was fed up after looking everywhere and groaned, "Has anyone seen my glasses?"
Remember that the word "I" is also capitalised in English, in contrast to many other languages, such as French, German and Spanish, which do not capitalise the first person singular pronoun. It's also useful to know that rules change over time. Several hundred years ago, "I" was not capitalised, and a couple of hundred years ago, many ordinary nouns were, as in modern-day German!
Have a go at our second Capital Letter quiz.