I had to put verbs in past tense.1.Necesité (necesito) medicine.

2.The doctor gave me a injection.
I had to change (da) to past but I don’t know the past tense.
3.Después, el doctor me dó(da) una receta ir a la famacia y comprar.

#2. The verb "dar" has these forms:

di, diste, dio, dimos, dieron. Because "u" and "i" are weak, an accent mark is not required. In OLD books dí & dió USED to have accent marks but no longer!

3. You "almost" had it but Spanish is "a Romance language" and "do" is far from romantic/pretty/musical, etc.

After you study Spanish a while, your "ear" will tell you whether it is wrong or right! :)

Sra

So (da) would be dio in number 2 when referring to the doctor?Sorry but I'm not sure?? Thank you

To put the verbs in past tense, you need to use the appropriate past tense endings for each verb. Let's go through each sentence and change the verbs to their past tense forms:

1. Necesité (necesito) medicine.
In this sentence, "necesitar" is the verb that needs to be in the past tense. The past tense of "necesitar" in the first person singular (yo) form is "necesité." So the corrected sentence would be: Necesité (necesité) medicine.

2. The doctor gave me an injection.
In this sentence, the verb "gave" needs to be in the past tense. The past tense of "give" is "gave." So the corrected sentence would be: The doctor gave me an injection.

3. Después, el doctor me dó(da) una receta para ir a la farmacia y comprar.
In this sentence, the verb "dó(da)" needs to be in the past tense. The correct past tense form is "dio" for the third person singular (él/ella/usted) form. So the corrected sentence would be: Después, el doctor me dio una receta para ir a la farmacia y comprar.

Remember to also make sure that the other parts of the sentence are consistent with the past tense form of the verb.