present perfect/present perfect progressive/simple past

[sitifan]

1. I have been teaching English for six months.
2. I have taught English for six months.
3. I taught English for six months.
#1 means "I started doing it six months ago and am still doing it."
#2 possibly means the same as # 1, or could mean that once in the past I taught English for a period of six months.
#3 means once in the past I taught English for a period of six months.
Am I right?

[2006]

1. I have been teaching English for six months.
2. I have taught English for six months.
3. I have taught English for six months.
#1 means "I started doing it six months ago and am still doing it." yes
#2 possibly means the same as no. 1, or could mean that once in the past I taught English for a period of six months. yes
#3 means once in the past I taught English for a period of six months. #3 is the same as #2
If you meant 'I taught English...', you are right. Please try to be more careful with your posts, so that we don't have to guess what you meant to say.
Am I right?

2006