1.

1. + My friend goes to the gym every morning. ( Present Simple )

2. - My friend doesn't go to the gym every morning. ( Present Simple)

3. ? Does my friend go to the gym every morning. ( Present Simple)

2.

1. + He wrote a letter last week. ( Past Simple)

2. - He didn't write a letter last week. ( Past Simple)

3. ? Did he write a letter last week. ( Past Simple)

3.

1. + They are playing computer games now. ( Present Continuous )

2. - They are not playing computer games now. ( Present Continuous )

3. ? Are they playing computer games now? ( Present Continuous )