English grammar rules: Time prepositions

English grammar rules: Time prepositions Hi! we heard three different prepositions; at, in and on. We use these prepositions when we're talking about time but we use each one with different time expressions. Example: In the morning, at 3 o'clock. In 2004. At midnight, on Christmas Day. In December. We use 'at' for times of the day. At half past 7, at midnight, at sunset at breakfast time. At 3 o'clock At midnight We use 'on' for days and dates. On the 5th of June, on Tuesdays, on Saturday morning. On Christmas day. We use 'in' for longer periods of time like months, years, seasons. In April, in 1987, in the winter of '76. In 2004 In December Finally, there are some time expressions that don't use any prepositions at all. Words like 'next', 'last', 'today', 'tomorrow' or 'yesterday'. Next Christmas we're going on a cruise.