My dear friends! Posting our grammar tests for rather long we see your main weak points. So, this week, we are posting two other tests.  Tanya will tell you about the gerund, while I will tell you a little about using the modal auxiliaries describing the past.
When we speak/write about the past (not the future past), we mostly use modals followed by the prefect/perfect progressive form of the infinitive. Let’s see, what they mean. I will use DO as a demonstrative verb.
COULD HAVE DONE may mean:
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