Why can I hear the person I am talking to but they can not hear me?

Hi @davidavald85935

Is the phone in a protective case at all?

If it is in a protective case, then remove it from the case and check if you can be heard when on a call?

If it is in a case and you still can't be heard when the phone has been removed from its case or if it wasn't in a protective case at all, try using a vacuum cleaner to clear the voice inlet hole next to the headphone jack on the bottom edge of the phone, in case it is blocked with lint etc. Do not use a pin or metal probe to try and clear it as you may damage the microphone that is located behind the voice inlet hole.

If still no good, can you be heard OK when in loudspeaker mode (aka hands free mode) on a call?

If you can then there may be a problem with the microphone which is located on the charge port board in the phone.