# fill in for

CEFR B1 · Phrasal verb

Source: https://englishreference.com/word/fill-in-for
Updated: 2026-04-24

## Definition

to do someone else's work for a short time because they are away or sick.

For teachers: to act as a temporary substitute for someone; typically used in professional or social contexts to denote a short-term replacement.

## Examples

- Can you fill in for me while I'm at the doctor?
- The assistant manager had to fill in for the director during her three-week maternity leave.
- Despite having little experience in logistics, Sarah was asked to fill in for the department head during the emergency summit.

## Pitfalls

- Not "I will fill in for his job." but "I will fill in for him." — you fill in for a person, not for a task or a position; you 'fill' a position but 'fill in for' a colleague.

## Usage notes

- usually followed by a person; implies the substitution is temporary.
- Teaching tip: contrast with 'stand in for' (very similar) and 'replace' (which often implies a permanent change); 'fill in' without 'for' can also mean to complete a form.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.