Prepositions + Gerund

After a preposition, use -ing.

Examples

• She is good at drawing.
• He left without saying goodbye.

Key rules

• After a preposition use -ing: good at drawing, interested in learning
• Never use the base verb or to after a preposition
• Common ones: without, before, after, instead of, by
• Wrong: look forward to see → look forward to seeing

Common mistakes

• She is good at draw → She is good at drawing
• He left without say goodbye → He left without saying goodbye