It's amazing what some people downvote. I didn't know that there is a fruit called 'citron' in English, so I looked it up. Very interesting. It is one of the three ancestral citrus fruits. All others are the result of crossings between them. (There are also close relatives such as the poncirus and the kumquat.) It seems strange that it was named after the cedar, but there are two connections: A somewhat similar smell, and the fact that the citron at some point before the Talmud replaced the cedar cone in the Jewish Sukkot ritual.
- The citron (citrus medica) was the first citrus fruit that was brought to Europe -- as a result of the wars of Alexander the Great. Its fruit normally look like lemons with an extremely thick rind that is sold dried. The citron is endemic in Southeast Asia. Some cultivars have a very weird shape in which the typical pocks that we know from lemon rind have turned into fingers.
- The pomelo (citrus maxima), also from Southeast or South Asia, first became significant to Europeans in the 17th century. Its first English name was shaddock, after the captain of the East India Company who introduced it to Jamaica. Its fruit resembles grapefruit, though it's typically even larger.
- The mandarin orange or mandarine (citrus reticulata) was first mentioned in China over 3000 years ago. It reached Europe around 1800.
The [sweet] orange and the bitter orange are Chinese hybrids between pomelo and mandarine. The grapefruit is the result of crossing the sweet orange back with the pomelo, one of its ancestors. Many modern mandarine-like cultivars are likewise the result of such crossings with an ancestor or with each other.
The lemon is a hybrid of citron and bitter orange, so it includes all three citrus species in its ancestry.
There are many different species commonly referred to as lime, with different ancestry. Some of them are not pure citrus fruits, or even totally unrelated.
I don't know where you are from, but at least in the parts of Europe where I have lived, limes are significantly rarer in supermarkets than lemons. Lemons are a common household staple; limes are not. If you run out of lemons it makes sense to ask your neighbour for one, as in the case of milk, eggs or flour. With limes that would be quite unusual.
@allintolearning: Ultimately that's the same thing because going back far enough (Proto-Germanic) we can't tell them apart.
Around the time of MystyrNile's "1500 years ago", there was a dialect continuum similar to the Romance one we have today that ranges from Portugal all the way to Italy. I.e. you can travel slowly from one end to the other stopping in every village and adapting to its dialect. Without even noticing, your language gradually turns from Portuguese into Italian. Without standardised national languages that situation was even clearer at the time. The ancestors of English and German (which for this discussion is equivalent to Dutch because German and Dutch parted ways much later) were at different locations in this dialect continuum. One can argue that they were dialects of the same language, but in fact they were probably not mutually intelligible without that experience of learning intermediate dialects while traveling.
If we go back another 1000 years we may well reach a small group of speakers all speaking the same (West Germanic) dialect.
'Heb' for first-person singular ('ik heb' = 'I have').
'Hebt' for second- or third-person singular ('jij hebt' = 'you have'; 'hij/zij hebt = he/she has').
'Hebben' for all plurals ('wij/jullie/zij hebben' = 'we/you/they have').
There's also an exception in that when you use inversion to form a question, the second-person singular takes 'heb' instead of 'hebt' ('heb jij een limoen?' = 'do you have a lemon?').
In standard English, jullie translates to plural you. However, the need to distinguish whether you mean to address just the person you are talking to or some wider group hasn't led to a revival of the old singular thou. Instead, you is now considered singular and many English speakers add various things to indicate the plural in colloquial speech. Sometimes the result is then abbreviated, as e.g. in you all → y'all. See here for a map of the current situation in the US. (The text below also has some limited information about other English-speaking countries.)
But it's important to understand that unless you are using a specific dialect that has progressed further, there is absolutely nothing wrong about using you to address several people, even colloquially. I am also under the impression that the UK is more conservative in this respect than the US. I never noticed any plural form of you when I worked at a British university for a few years, and I was quite stunned when I realised how common they have become in the US. Some early Duolingo courses initially even required the use of you all when translating to English, but I think that wasn't correct even in whatever local US context that came from, and it was quickly corrected.
In Dutch, the same thing happened earlier because the analogous construction could optionally be used with the plural pronouns even when the singular pronouns were still in common use. (More precisely, one could say the contemporary Dutch equivalent of we people, you people, they people instead of just we, you, they.) Consequently, when du (thou) was lost, speakers could immediately start to use je lieden (you people) or some of its many variants, one of which is ju lieden, to distinguish the plural. Over time this was shortened to jullie just like the southern half of the US recently has shortened you all to y'all. Etymologiebank.nl on jullie.