The Russian word for devil is чёрт. It's a bit irregular because it becomes soft in the plural, thus it declines like this:

In English it sounds rather quaint to say "Go to the devil," but in Russian the phrase is much stronger and not quaint at all. To catch the emotional color of it in English, it is best to translated it as "Go to hell":

Another way to say about the same thing is to literally say "The devil with you":

In the US many Christians consider it offensive to take the Lord's name in vain. In Russia it is more offensive to swear using the word "devil." Interestingly enough, by saying "to God with him" they can express indifference or minor irritation. It's not nearly as strong as saying "The hell with him" and can be said in polite company, so I think it is best to translate those phrases into English with "To heck with him/her":

Of course, if you are a sensible foreigner, you aren't going to go around Russia telling the Russians to go to hell, but you will still encounter the word in real life, art, and literature. My favorite "to hell with you" is in a song by Веня Д’ркин called «Ты нравишься мне» “I like you”. Ah, rage and betrayal and desperate love all wrapped up in one melodious package. You can listen to the song here, along with a translation.

The word for Monday in Russian is понедельник. First a bit of history. The verb "to do" is делать. "To not do" thus is «не делать», and in ancient Russian one of the words for Sunday was неделя "the day on which you do nothing". The preposition по means after, and the suffix -ник forms a noun, thus the word понедельник means "the day after Sunday." Cool, huh? Of course nowadays nobody thinks about that history when they say понедельник. They just think of the first day of the week.

Some Americans say things like "I hate Mondays." The most common phrase about Monday in Russian is «Понедельник — день тяжёлый» "Monday is a tough day."

Though it is easy to memorize the days of the week in Russian, English speakers will need to keep in mind the prepositions that are used with them. If you want to say that something happened (or will happen) on a particular Monday, then you want the preposition в followed by the accusative case:

If you go there every Monday, then you want the preposition по followed by the dative plural:

If something started on Monday and is still continuing, you want the preposition с followed by the genitive case:

And if you want to give a range of days over which something will happen, for the starting day you use с + genitive and for the ending day you use the preposition по + accusative:

Last but not least, of course, you use the word in the nominative case when answering what day of the week it is:

¹ Some of my native speaker informants prefer the preposition до + genitive in this context along with the adverb включительно inclusively. Thus:

Growing up in the US, children commonly say things like "Me and Johnny went to the store." Although it sounds perfectly normal to many people, it is considered terrible written style (and also bad style for public speaking), and grade-school teachers make a great effort to break kids of this habit. The only acceptable written form is "Johnny and I went to the store."¹ If we transform that word-for-word into Russian, we get the sentence «Иван и я ходили в магазин». Although every Russian will understand such a sentence, it is not the most typical way to say it. Instead the more common way is:

The phrase «мы с Иваном» is actually ambiguous. It can mean "John and I" or it can mean "We (a group of two or more people) and also John". The same holds true for the phrase «мы с ним», which can mean "he and I" or "we [two or more people] along with him." For instance, if my wife and I are having pity on our poor, miserable bachelor friend, John, I can say:

Although the second translation is the more natural way to put it in English (and thus the better translation on this occasion), the first translation captures the idea that John is included in the concept of мы in the sentence.

On the other hand, if I go to the movies with John but my wife does not come along, the same construction just means me and John:

The same ambiguity holds for the phrase «вы с Иваном», which can mean "you [one person] and John" or "you [more than one person] and John. For instance, let's say I'm talking to a female friend about her son Женя. If I want to ask whether she often argues with him, I might ask:

Or if I am taking to both her and her husband, I might say the same thing with a different meaning:

The same holds true for phrases with они, which can be interpreted a variety of ways. Let's say I'm talking about my female friend who is feeling sorry for another female friend. This sentence could result:

Of course, if my friend's husband also feels sorry for Vera, we could have a parallel sentence:

The same situation also of course applies if my friend is a man:

To review, the phrases «мы с ним», «вы с ним», «они с ним», «мы с ней», «вы с ней» and «они с ней» are ambiguous in that they can refer to groups of two or more people.

¹ Actually, the teachers do too good a job of breaking us of that habit without explaining the situation more thoroughly. In fact many teachers overgeneralize and just teach their students that any time they are tempted to say "me and you" (or any other combination of "me and..."), they must replace it with "you and I" (or "... and I"). Even very educated people — sad to say that among them are my own mother and sister — thus will say things like, "Just between you and I, I think that is a bad idea." The correct thing to say in that context is "Just between you and me..." But just try to convince them of that... it's a lost cause.

² In this context with the third-person plural pronoun, some native speakers prefer «Ей очень жалко Веру, поэтому она с ней часто ходит в кино», but in rapid speech the «они с ней часто ходят» form is entirely possible.

³ In this context with the third-person plural pronoun, some native speakers prefer «Ему очень жалко Веру, поэтому он с ней часто ходит в кино», but in rapid speech the «они с ней часто ходят» form is entirely possible.

We mentioned the other day that the preposition "с" + the instrumental case means "with." There is another context where it means "with," but we don't translate it as "with," and that is when two nouns are joined together as the subject (or object) of a sentence. In these contexts we must translate "с" as "and." For example:

In this context translating "с" as "with" sounds terrible in English and is a grammatical error.

The preposition "с" has several meanings and can be used with several cases. When "с" means "with" it is followed by the instrumental case:

One thing a beginner has to watch out for is that sometimes you must NOT use "с" in translating the English word "with." This is particularly true when indicating the "means by which" you do something. This is the "pure instrumental" meaning of the instrumental:

In those last three examples it would be wrong in Russian to include "с".