Grammar In Use - Pre-intermediate -
Describing a background action interrupted by a shorter one (e.g., "I was walking home when it started to rain").
For likely future events (e.g., "If it rains, I will stay home"). Grammar in Use - Pre-intermediate
These structures help you describe relationships between things and people. Modals of Probability and Obligation Ability in the present and past. Describing a background action interrupted by a shorter