estômago

o dor

de garganta

de cabeça

pain, ache

sore throat

headache

Using 'por'

1. Movement

2. Time

3. Action

4. Other uses

1. through or by a place - through

2. duration of an event - for

3. reason or motivation of action - because

4. indicate exchange or execution

5. express unit or exchange rate

6. express 'instead of'

7. approximate time

Using 'para'

1. Movement

2. Time

3. Action

4. Other

1. towards a Destination -to

2. action deadline - by

3. for whom something is intended or done - for

4. express judgement or point of view

5. express intention followed by infinitive(in order to)

pelo

pela

pelos

pelas

1. vamos + Infinitive

or

2. Nós form of the subjunctive