Gardeningregularly is his hobby, but weeding the overgrown flower beds istiringtask.
The underlined parts are respectively -

• Gardening regularly is his hobby, but weeding the overgrown flower beds is a tiring task.
- The underlined parts are respectively - Gerund and participle.

• Gerund:
- Verb এর সাথে ing যোগ হয়ে যদি noun এর কাজ করে অর্থাৎ Verb ও noun এর কাজ করে, তাহলে তাকে Gerund বলে।
- সংক্ষেপে: Gerund = Verb + ing = noun = Verb + noun.
- It is a word ending in "-ing" that is made from a verb and used like a noun
- Gerunds don’t describe action—they act as nouns.

• সুতরাং নিয়মানুযায়ী, এখানে, বাক্যের subject হিসাবে Gardening হচ্ছে gerund এর উদাহরন।

• A participle is a verb that ends in -ing (present participle) or -ed, -d, -t, -en, -n (past participle). Participles may function as adjectives, describing or modifying nouns.
- Participle একই সাথে Verb ও Adjective এর কাজ করে।

• Participle মূলত: তিন প্রকার: 
1. Present Participle. Ex: Do not disturb a sleeping dog. 
2. Past Participle. Ex: This is a book written by Charles Dickens. 
3. Perfect Participle. Ex: Having eaten rice, he went to bed.

• প্রদত্ত বাক্যে tiring হচ্ছে present participle.
- এটি verb = ing যোগে গঠিত হয়ে তারপরে অবস্থিত noun task কে modify করছে এবং indicating that the task of weeding the overgrown flower beds is tiring.