What kind of Field Research quests are there?

Question

I have seen a couple of predictable Field Research quests, like "catch X of Y", but also less normal quests, like "spin 3 PokéStop you haven't visited before". What are all the different type of quests?

Answer 1

This GameRant article contains all Pokémon Go research quests, based on a datamine:

• Battle in a Gym
• Battle in a Gym multiple times
• Battle in a raid
• Battle in a raid multiple times
• Use a super effective Charged Attack in a Gym battle
• Use a supereffective Charged Attack in multiple Gym battles.
• Use multiple Berries to help catch Pokémon.
• Use a Berry to help catch a Pokémon.
• Catch multiple Pokémon.
• Catch a Pokémon.
• Catch multiple Ditto.
• Catch a Ditto.
• Catch multiple Oddish or Bellsprout.
• Catch an Oddish or Bellsprout.
• Catch multiple Swablu.
• Catch a Swablu.
• Catch multiple Pidgey or Murkrow.
• Catch a Pidgey or Murkrow.
• Catch multiple Treecko or Mudkip.
• Catch a Treecko or Mudkip.
• Catch multiple Meowth or Skitty.
• Catch a Meowth or Skitty.
• Catch multiple Bug-type Pokémon.
• Catch a Bug-type Pokémon.
• Catch multiple Dark-type Pokémon.
• Catch a Dark-type Pokémon.
• Catch multiple Dragon-type Pokémon.
• Catch a Dragon-type Pokémon.
• Catch multiple Electric-type Pokémon.
• Catch an Electric-type Pokémon.
• Catch multiple Fairy-type Pokémon.
• Catch a Fairy-type Pokémon.
• Catch multiple Fighting-type Pokémon.
• Catch a Fighting-type Pokémon.
• Catch multiple Fire-type Pokémon.
• Catch a Fire-type Pokémon.
• Catch multiple Flying-type Pokémon.
• Catch a Flying-type Pokémon.
• Catch multiple Ghost-type Pokémon.
• Catch a Ghost-type Pokémon.
• Catch multiple Grass-type Pokémon.
• Catch a Grass-type Pokémon.
• Catch multiple Ground-type Pokémon.
• Catch a Ground-type Pokémon.
• Catch multiple Ice-type Pokémon.
• Catch an Ice-type Pokémon.
• Catch multiple Normal-type Pokémon.
• Catch a Normal-type Pokémon.
• Catch multiple Poison-type Pokémon.
• Catch a Poison-type Pokémon.
• Catch multiple Psychic-type Pokémon.
• Catch a Psychic-type Pokémon.
• Catch multiple Rock-type Pokémon.
• Catch a Rock-type Pokémon.
• Catch multiple Steel-type Pokémon.
• Catch a Steel-type Pokémon.
• Catch multiple Water-type Pokémon.
• Catch a Water-type Pokémon.
• Catch multiple Grass-, Fire-, or Ground-type Pokémon.
• Catch a Grass-, Fire-, or Ground-type Pokémon.
• Catch multiple Pokémon with Weather Boost.
• Catch a Pokémon with Weather Boost.
• Evolve a Pokémon.
• Evolve multiple Pokémon.
• Evolve multiple Fire-type Pokémon.
• Evolve a Fire-type Pokémon.
• Hatch multiple Eggs.
• Hatch an Egg.
• Pokemon GO Easter event number eggs hatched
• Make multiple Excellent Throws.
• Make an Excellent Throw.
• Make multiple Great Curveball Throws.
• Make a Great Curveball Throw.
• Make multiple Great Throws.
• Make a Great Throw.
• Make multiple Curveball Throws in a row.
• Make multiple Excellent Curveball Throws in a row.
• Make multiple Great Curveball Throws in a row.
• Make multiple Great Throws in a row.
• Make multiple Nice Curveball Throws in a row.
• Make multiple Nice Throws in a row.
• Make multiple Nice Throws.
• Make a Nice Throw.
• Power up Pokémon multiple times.
• Power up a Pokémon.
• Spin multiple PokéStops you haven’t visited before.
• Spin a PokéStop you haven’t visited before.
• Spin multiple PokéStops.
• Spin a PokéStop.
• Win multiple Gym battles.
• Win a Gym battle.
• Win a level 3 or higher raid.
• Win multiple level 3 or higher raids.
• Win multiple raids.
• Win a raid.
• Reach a specific level.
• Earn a silver Kanto medal.
• Earn a gold Kanto medal.
• Earn multiple Candies walking with your buddy.
• Earn a Candy walking with your buddy.
• Evolve a Magikarp

Answer 2

The possible Pokemon rewards for the various research quests are shown in the figure below. Note that it is possible to get also other rewards for the same quest (e.g. berries). If multiple Pokemon are shown, you can only get one of them (at random).