I am reading (well, have now finished) L'etranger by Albert Camus. It's made significantly easier by the fact that I can look words up on my ereader. However, the ereader doesn't allow looking up verb conjugations, meaning that automatic lookups are mostly limited to the infinitive form. As the infinitive doesn't occur very often, this means that lots of manual lookups happen.

Most of the sentences seem to be written in the 'passé composé' with the verb 'avoir'. eg j'ai mangé = I ate. I initially mentally translate this as the English present perfect -- "I have eaten". I then need to mentally reshape it into the English simple past "I ate".

Some of the hardest parts:

Words meaning when -- alors, quand, lorsque. I don't have a clue what the rule is for these if there is any, and they all seem to have a bunch of different other meanings.

Words meaning 'still' -- toujours, encore, quand meme. I don't get the rule for this.

The word plus -- Such a simple word and seemingly with only one concrete meaning yet it's deployed in thousands of different shades of meaning, and a surprising number of the usages are not particularly obvious. I think I basically never recognize the negative variation ne...plus, "not any more".

Irregular past participles -- I basically have to remember all of these because I don't write them down. Luckily there aren't that many of them, but some of them are a pain -- particularly the irregular verbs with voir endings have past participles that often seem bizarre.

Conjugations of être -- The fact that être conjugates into forms that start with s- and forms that start with e- is a never-ending source of bewilderment. It helps to remember that the verb is formed from mashing together the Latin verbs forms esse and stare. The future tense of être is particularly confusing.

Various meanings for sentence with on as the subject -- I haven't quite grasped how to deal with this because it seems like there are maybe 3 different forms of this? One is the "us" meaning, one is an impersonal pronoun (like English 'one'), and I feel like there's one other form. Having reread about this now, the confusion makes sense, as we don't have quite such an ambiguous pronoun in English.

The ne...que construction meaning only -- this normally causes a big double take, if I can even recognize it at all, and I misread all of these sentences until I learned about it.

Multi-word phrases (idioms) are very difficult. These are used all over the place and they can't be looked up in the dictionary. There's really no choice other than rote memorization of these.

I created an Anki deck from all of the vocabulary that I wrote down, this has every card tagged with parts of speech, and with limited English translations based on the usage in L'etranger.