In, After, Ago
Learn to express future intervals ('in ten minutes'), past distance from now ('three years ago'), and avoid the common error of using 'after' for fixed intervals from the present.
In, After, Ago — Intervals and Distance in Time
Three expressions handle time measured as a gap from the present moment. Each has a distinct grammar and a distinct meaning, and mixing them — particularly using after where in is required — is one of the most reliable markers of L1 interference at B1–B2 level, especially for Russian and other Slavic language speakers.
In + Time Period — From Now, Looking Forward
In + a duration means 'after that amount of time from now'. It points to a future moment:
The train leaves in twenty minutes — we'd better hurry.
I'll call you in a few days.
Ago — From Now, Looking Backward
Ago counts a distance back from the present. It always follows the time expression and is used with past simple (not present perfect):
She graduated from university two years ago.
I started this job six months ago.
After — Sequence, Not Interval from Now
After in time expressions describes a sequence: 'after the meeting', 'after dinner', 'after arriving'. It does not express a fixed interval from the present moment. Using 'after five minutes' to mean 'in five minutes' is a direct translation error for many learners:
✓ After the meeting, we went for coffee. (sequence — correct use of 'after')
Common Mistakes
✗ The bus arrives after fifteen minutes. → ✓ The bus arrives in fifteen minutes.
✗ We met before three years at a conference. → ✓ We met three years ago at a conference.