Question

What is the difference between the sentences
1. I also went there yesterday.
2. I went there yesterday

Answer 1

the first sentence means that the speaker was present at the place with others i.e he or she was included while the second one means the he or she was simply present at some place he or she is talking about

Answer 2

I also went there yesterday means that he went to a particular place the previous day but went to some other place too which is mentioned by using also in the sentence
While I went there yesterday means that the person went to one particular place only