At/On/In

Veja as frases abaixo:

• She arrived at 3 o'clock
• She arrived on Sunday
• She arrived in May. She arrived in 2005.

Assim devemos usar:

• at para as horas: at 4 o'clock, at 11.30, at midnight, at lunchtime, at sunset etc.
• on para datas e dias: on 25 April 2007, on Christmas Day, on my birthday, on Friday(s).
• in para períodos longo: in May, in 2005, in the 21st century, in (the) summer, in (the) future.

Não se usa at/on/in antes de last, next, this, every:

• I will be there next Sunday(e não on next Sunday)
• He was hired last March.

That's all for now folks. Enjoy your studies.

Take care.