Time prepositions: in, on, at

IN Months, seasons, years, centuries	ON Days and dates	AT Hours of the clock, points in time
in June in spring in 1890 / in the sixties in the past century in the future	on Monday on Sundays on November the 5th on his birthday on his wedding on New Year’s Eve	at 2 o’clock at noon / night at the moment at the end of the month

Expresssions:

In: in the afternoon (s); in the evening (s); in the morging (s) 
On: on Monday evening; on weekends
At: at night; at Easter; at the same time

If you use LAST, NEXT, EVERY or THIS DON'T USE "on", "in" or "at"

I was happy last Monday (in last Mnday)
I'm planning to go on holiday next Tuesday (on next Tuesday)
I eat yoghourts every Christmas (not at every Christmas)
I will take a walk this evening (not in this evenig)

Exercises

Prepositions of time 1 

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