In some ways, the quartet of words love, like, don’t like and hate runs in parallel to the quartet of hot, warm, cool and cold. Love, like and hate have been part of English for over a thousand years, and have recognisable cognates in the other West Germanic languages. Hot, warm, cool and cold can be modified by very, so and too; love, like and hate can be modified by really, so much and too much to describe a continuum of human emotions.
Dictionary.com (based on the Random House Dictionary) has 14 definitions of love as a noun (covering: another person, a parent, child, or friend, sexual intercourse, neighbours, books, theatre, God and tennis (which probably has a different derivation), seven as a verb (with much the same scope, and also ‘Plants love sunlight’), and seven as a phrasal verb (love up, for love, for the love of, in love, in love with, make love, and no love lost).
Like is given six definitions as a verb (covering ‘the concert’, ‘his parents’, ‘as/whatever you like’ and ‘approval on Digital Technology’), two as a noun (‘likes and dislikes’ and ‘Digital Technology’), and one as an adjective (‘a Like button’). There is also the very strange verb string would like. Completely separate are the adjective, preposition, adverb, conjunction and noun like, which has, like, a totally different derivation.
Don’t like, doesn’t like and didn’t like have overtaken dislike, dislikes and disliked in the last 40 years, for no reason I can think of. Dislike possibly has a more strongly negative flavour: you can ‘not like’ someone or something and instead be completely indifferent about them or it. (In fact you can also ‘not like’ something and instead ‘love’ it.) Dictionary.com gives the examples of ‘I dislike oysters.’ which I totally understand, and ‘a strong dislike for Bach’ which I totally don’t. Intriguingly, ‘dislike’ wasn’t recorded until the mid-16th century, more than 600 years after ‘like’. Did people not dislike things for all that time, or did they find other ways to express it?
Digital Technology has also given us unlike as a verb, which some people have complained about, but ‘unliking’ a post or photo on Facebook isn’t the same thing as ‘disliking’ it. (Dictionary.com doesn’t, in fact, record this meaning.)
Hate is given just three definitions as a verb (covering ‘the enemy’, ‘bigotry’ and ‘to do it’).
I advise my students to be very careful about using love and hate; different cultures have different ideas about exactly whom one can use the word love to or about, and hate is a very strong word. I said at the start that ‘in some ways’ love etc parallel hot etc, which might imply that ‘hate is cold’. On the contrary, one’s hates often end up being hotter than one’s loves. The writer Elie Wiesel said, ‘The opposite of love is not hate, it’s indifference’ and various other writers have expanded on that.