I forgot to include the following sentences.

1) I had a stomachache OR I had stomach ache?
2) I have a terrible sore throat. I think you should take a dose (can you say an effervescent tablet) of anti-inflammatory after main meals (lunch, dinner) and a tablespoonful/teaspooful of syrup before going to bed. (a cup of hot milk with honey?)
3) I think you should go to a physotherapist and have a massage.
4) I cut my finger while I was slicing some bread. The surgeon put five stitches on my finger.
5) I fell off the hose and I broke my right ankle. I had my leg put in plaster. (I had a cast on my leg for a month. OR I was in a plaster for a month).
6) The doctor prescribed a painkiller to be taken twice a day on a full stomach.
7) As I had diarrhoea the doctor prescribed milk enzymes to be taken on an empty stomach.
8) I think you should go to the eye specialist (not 's) and have your eyes tested. I think you should have your blood pressure taken and your blood tested.

1. Keep "a"

2. Delete the words in parentheses. The rest is fine. (I don't think an antacid will help with a sore throat, though!!)

3. spelling --> physiotherapist

4. in my finger (not "on...")

5. I fell off the ______. (Do you mean "house"?)
"I had a cast on my leg for a month."

6. - OK

7. - OK

8. Right -- no 's on "specialist"

1) The correct sentence is "I had a stomachache."

To determine the correct form, you can break down the sentence. In this case, "stomachache" is a noun, and we use the indefinite article "a" before nouns. Therefore, it is correct to say "I had a stomachache."

2) I have a terrible sore throat. I think you should take an effervescent tablet of anti-inflammatory after main meals (lunch, dinner) and a tablespoonful/teaspoonful of syrup before going to bed. You can also try having a cup of hot milk with honey.

In this sentence, we need to use the indefinite article "an" before "effervescent tablet" because it begins with a vowel sound. Both "tablespoonful" and "teaspoonful" can be used depending on the quantity you want to take. Finally, drinking a cup of hot milk with honey can also help soothe a sore throat.

3) I think you should go to a physiotherapist and have a massage.

To correct this sentence, it should be "physiotherapist" instead of "physotherapist." Additionally, the verb "have" is used correctly to indicate that the subject should receive a massage.

4) I cut my finger while I was slicing some bread. The surgeon put five stitches on my finger.

In this sentence, there are no errors. The verb "put" is used correctly to describe the action of the surgeon placing stitches on the finger.

5) I fell off the horse and I broke my right ankle. I had my leg put in plaster. I had a cast on my leg for a month.

The correct phrase to use is "I had my leg put in plaster." Alternatively, you can say "I had a cast on my leg for a month." Both expressions are correct and commonly used to describe having a broken bone immobilized using a cast.

6) The doctor prescribed a painkiller to be taken twice a day on a full stomach.

In this sentence, there are no errors. The doctor prescribed a painkiller to be taken twice a day, specifically on a full stomach.

7) As I had diarrhea, the doctor prescribed milk enzymes to be taken on an empty stomach.

In this sentence, there are no errors. The doctor prescribed the intake of milk enzymes on an empty stomach to address the condition of diarrhea.

8) I think you should go to the eye specialist and have your eyes tested. I think you should have your blood pressure taken and your blood tested.

In this sentence, there are no errors. The recommendation is for the person to visit an eye specialist for an eye test and also have their blood pressure and blood tested.