A: Could have + past participle means that something was possible in the past, or you had the ability...

English speakers often use THE plus a singular noun when they talk about or make generalizations about...

An infinitive is the "to" form of the verb. The infinitive form of "learn" is "to learn." You can also...

A gerund is a noun made from a verb by adding "-ing." The gerund form of the verb "read" is "reading."...

The prepositions at, in and on are associated with specific time categories, Usages are as follows.1....