Visualize bc the pictures help to view the perspective using you eye balls
1. Non-essential - A title usually is the result of hard work, therefore, it's not necessary to include that appositive phrase.
2. Essential - It tells you who the Keystone Corps are. Otherwise, you would have no idea.
3. It's non essential.
1. Infinitive tense is the verb in the 'to' form, so you got it right there: to climb.
2. Third person singular present tense is the present tense plus the letter 's' at the end because it is in third person.: climbs
3. Past tense is something that happened in the past: climbed
4. Participle is like the -ing form.: climbing