Students have asked me to review the difference between using the gerund and past participle to replace clauses. The gerund can replace either a simple present tense or a present or past continous. The past participle (ED) can only replace a PASSIVE verb or a complement.

My lecture in a nutshell:
  • Combining sentences makes for more interesting and more sophisticated (read: more C1/C2). 
  • To do so, one of the techniques is replacing clauses with present or past participles (read: ing or having ed or ed). 
  • Students don’t always do this well- the two common errors are 
  • A . using ED when it’s NOT A clause with “be” … i.e., neither passive nor complementary
so, 
Arrived at the store, she bought milk. 
 
is INCORRECT. 
 
As you are replacing “When she arrived” (ACTIVE =no verb to be), you need
HAVING ARRIVED or ARRIVING.
 
ALSO 
  • B. misplacing the ED past participle, again due to thinking in terms of active vs passive verbs. 
so, 
FOUND HER KEYS, she drove to work.
 
is INCORRECT. 
 
if you say FOUND HER KEYS … the verb is active (After she found her keys … ergo …. After finding her keys)
but you COULD also say    … Once her keys WERE FOUND .. so verb BE .. SO
 
HER KEYS FOUND, she drove to work …is CORRECT.
 
Walking through the forest, Little Red Riding Hood met a wolf. (yes =while she was walking) Talking to the wolf, Little Red Riding Hood disobeyed her mother.(yes=because she was talking)

NO     Arrived first at the cottage, the wolf disguised himself as LRRH’s grandmother (NO!! This is not a passive  or complementary  verb. You should use “having arrived at the cottage before LRRH)

YES   Eaten by the wolf, LRRH never came home.(A horrible sentence but grammatically OK, as it is passive)

YES  Concerned that LRRH hadn’t yet returned, her mother called her friend the hunter.(This is OK because it’s a complement with the verb to be = because she was concerned)

for more, see these links

http://www.ego4u.com/en/cram-up/grammar/participles (scroll down to the end)

and exercises

http://www.ego4u.com/en/cram-up/grammar/participles/exercises?06

and I’ll post a quiz soon.