AGO
• We use ago to talk about a time in the past.
We use it with the Past Simple: I went to Mexico two years ago.
(= two years before now).
LAST
• We use last to say the day, week, etc. in the past that is nearest to now: I went dancing last Saturday.
(= the Saturday before now).
• We use last with days (last Tuesday), months (last March) and in these phrases: last night, last week, last weekend, last month, last year, last century.
TIPS!
• We say last night, but we say yesterday morning/afternoon/evening NOT last morning, etc.
• We don’t use a preposition with last: last weekend NOT in last weekend, last month NOT at last month.
IN
• We use in with years (in 2005) and months (in May).
• We use in the with decades (in the nineties) and centuries (in the twenty-first century).
TIPS!
• We can use on with days (on Monday) to mean last: I met him on Monday. = I met him last Monday.
• We use at with times (at ten o’clock).
centuries night with Past month
decades now
•week century
dancing last last last Simple last Mexico week preposition last with past years last last months last last before etc
•ago
Tuesday yesterday year with before years last time nearest last last Monday times last days
•last nineties