Here’s a study: Study: Mnemotechnics in Second Language Learning
It really depends on the language I’d say. Syllable based languages are great because you have a limited amount of combination (and some combinations only ever appear in front or at the end of a word). In Chinese phonetics you only have 50 or so different syllables until you add the tones. There is a method called the marilyn method in which you attach a person to every possible front-syllable in Chinese (for instance sh=Sherlock, zhu=maybe a pig because 猪 (which means a pig) is pronounced like zhu). You then need several locations (bigger areas like a city) to match all the ending syllables (for example -an as in yu/-an) which each have four or five different locations to tell you which tone the syllable has (Chinese has four different tones + a neutral tone). I imagine it would work similar with other syllable based languages.
Similarly, with Chinese characters you can attach meanings to the regular components and thus create a story for every character. By additionally attaching locations to components which only ever appear at the bottom, side or top you can use a rudimentary memory palace.
To learn indogermanic languages I just use rote learning (i.e. Anki or lingvist) and focus on translation (because it’s the best simulation of the real thing) + finding a language partner (which allows you to actually do the real thing i.e. speaking).
As well as words that are semantically related, there are words that are phonetically or visually related.
For such words, you might want to try the keyword method, explained here:
The example in that link shows how to remember that the Spanish word carta links to the English word letter by using the English KEYWORD cart.
BTW: The example image for letter -> cart is tame and uninspired: “letter in cart”. It’s not very memorable for me.
For a memorable image, you you need sound, smell, movement, ridiculosity, bizarreness, and so on.
Better might be an out-of-control cart racing down a steep hill - metal wheels grinding and sparking on the cobbles, the smell of burning axle grease, millions of letters flying out of the cart, each letter flying into the correct letter box.
In the example in your OP:
- fridge -> barad
The ENGLISH keyword could be any of:
- bar (a round bar, a cocktail bar)
- Barr (Bill Barr of impeachment fame)
My image to link fridge to bar would be a round metal bar pounding a defenceless fridge into scrap metal. Hear the noises of the bar hitting the fridge, which is begging for mercy (Note: this is not @mercy, a respected user of this forum, who has never been known to hit defenceless fridges) . Hear the heart-rending screams of the fridge. Smell the delicious odour of roast beef with Dijon-caper sauce emanating from the fridge.
To enter fridge and barad in Anki, I would use two cards:
- Front: fridge
- Back: the image, then lower down, barad
- Front: barad
- Back: the image, then lower down, fridge
Sorry for jumping in this discussion a little late.
I feel that the best way to jump start language learning is by learning songs: first listen to the song on youtube, than find the song lyrics in the actual language an it’s translation (just google song lyrics translation).
I started learning Spanish by using “La camisa negra” form Juanes, a song that already stuck in my head beforehand.
In addition to this mehod I had the “Spanish for dummies” book and some “Spanish for travelers guide” type of book.