If a task is tiring, it makes you feel tired. Many things can be tiring, like waiting in line, filing out forms, doing certain kinds of housework.
Tiresome is an adjective that describes a person or activity that makes you feel bored and/or annoyed. So it's a bit different from tiring, because there's a more negative and emotional meaning. Here are a few examples:
You: How are you?
Your friend: Not that great. I've been in a really tiresome meeting for the last two hours, talking about the same things over and over again and not getting anywhere.
*****
You: Do you ski?
Your colleague: Not really. I used too, but the whole process was just too tiring. All that preparation and expense for such a short time actually skiing!
Tiresome is an adjective that describes a person or activity that makes you feel bored and/or annoyed. So it's a bit different from tiring, because there's a more negative and emotional meaning. Here are a few examples:
You: How are you?
Your friend: Not that great. I've been in a really tiresome meeting for the last two hours, talking about the same things over and over again and not getting anywhere.
*****
You: Do you ski?
Your colleague: Not really. I used too, but the whole process was just too tiring. All that preparation and expense for such a short time actually skiing!