This and these are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
This is a singular pronoun. It is used to draw attention to specific thing, person, place, idea, object, in relation to the speaker. Usually “this” is what the speaker wants, what the speaker thinks, what the speaker prefers.
These is the plural pronoun form of this. It is used to draw attention to a group of things, people, objects, places, or ideas in relation to the speaker.
The following story uses both words correctly:
Thisbe was planning her wedding with her mom. Today, they were at the florist. The florist asked what her flower preferences were. She replied, “I like these white hydrangeas.” Her mom asked, “What about these peach roses?”