TASK DEFINITION: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
PROBLEM: If I were to try to achieve something you could say I 'had a go'. If I tried it multiple times, how would I write that down? I had many goes or I had many go's or I had many gos.

SOLUTION: The dictionaries I've checked seem to be unanimous that the plural of the noun 'go' is 'goes'. I didn't see one list its plural as 'gos'. However, I didn't check all dictionaries. American Heritage Dictionary: n. pl. goes Collins Dictionary: n, pl goes Merriam-Webster Dictionary: plural goes Cambridge Dictionary: plural goes Random House Unabridged Dictionary (dictionary.com): plural goes Google NGram Viewer does not show any results for 'two gos at' or 'two gos at', but does when written as 'goes'. A Google search shows the following results: 'two gos at' = 453 results. 'two goes at' = 19,500 results. 'three gos at' = 252 results. 'three goes at' = 20,200 results. Note that both Google search and Ngram Viewer may show false positives, as Google search, as far as I know, doesn't take punctuation into account when giving search results, ie., full stops, commas. But I think it's safe to assume the consensus is that the plural of go (attempt or try) is 'goes'. I think this is a good question, as somewhere in my head I have an instinct to write it 'gos'. However the answer is gotten easily by checking some dictionaries. Also, if you wrote 'I had three gos at it before giving up', I have a feeling the typical reader probably wouldn't even be surprised by it or notice it particularly as wrong. This is just my opinion. I have this feeling because the '-os'/'-oes' plural ending rules are wildly inconsistent. Potatoes, tomatoes and heroes are correct. But 'photos' and 'burritos' are correct. However most dictionaries seem to list either '-os' or '-oes' ending as acceptable in 'ghetto' and 'mosquito'. Both 'mosquito' and 'burrito' most likely come from Spanish, yet most dictionaries say only 'mosquito' can have plural ending either '-os' or 'oes', whereas they're consistent in listing '-os' for burrito plural. Same goes for 'canto', 'manifesto' and 'grotto'. These words most likely come from Italian, yet the plural of 'canto' is 'cantos', whereas the dictionaries say the plural of 'grotto' or 'manifesto' can end in either '-os' or '-oes'. Addendum As some people have claimed that the rules for -os or -oes plural endings are quite consistent (and I happen to disagree), I've included more examples to show just how unpredictable this can get. The claim generally is basically that borrowed words or imported words from other languages have -os as their endings and most everything else has -oes. The more specific claim is this rule applies for words from Romance languages specifically. embargo (Spanish): Dictionaries show only -oes plural. NGrams show -oes much more common. tornado (Spanish): Dictionaries show either -os or -oes plural. NGrams shows -oes much more common. desperado (Spanish): Dictionaries show either -os or -oes plural. NGrams shows -oes more common. cargo (Spanish) plural possibly as the pants: Dictionaries show either -os or -oes. NGrams shows -oes more common. mango (Portuguese): Dictionaries show both -os or -oes. NGrams shows -oes much more common. domino (uncertain exactly which language, but a Romance one, or maybe directly from Latin): Dictionaries give either -os or -oes. NGrams shows -oes much more common. volcano (Italian): Dictionaries give either -os or -oes. NGrams shows -oes much more common. motto (Italian): Dictionaries give either -os or -oes. NGrams shows -oes to be more common. Words taken directly from Latin many times have -oes plural ending, but not always: veto has plural vetoes torpedo has plural torpedoes However memento overwhelmingly has plural mementos. And embryo is always embryos. Echo, directly from Greek, has plural 'echoes'. hello (native English): Nearly always 'hellos'. no (native English): Much more common as 'nos', ie., 'yeses and nos'. do (native English): Dictionaries give plural as either 'dos' or 'do's'. The results for searches of these terms would be confounding to say the least. weirdo (native English): some dictionaries show both -os or -oes. NGrams shows -os is much more popular Unknown origin: hobo: Dictionaries give either -os or -oes. NGrams show roughly same frequency. gizmo: = Dictionaries only give -os, 'gizmoes' doesn't show anything in NGrams. gazebo: Dictionaries show both -os or -oes. NGrams shows -os more common. So I don't know about anyone else, but I personally need help, in many ways.

PROBLEM: Possible Duplicate: Why don't we use the indefinite article with 'software'? In France I have always been told that saying 'a software' is not correct English (as a nominal compound), and that 'a piece of software' or 'a software program/package/product/system' must be used instead. Recently I have doubts... is there any case where it is actually correct? Examples found on the Internet: SalsaJ, a software for data analysis at school So if you sold a software which required your customer to pay a monthly fee, [...].

SOLUTION: No, this is always wrong. Both examples you provide contain incorrect usage of the term 'software.' (A mistake is still a mistake even if many people make it.) However, there might be special cases where you'd see the article preceding software. For example: A software solution would be better for the problem than a hardware one. The indefinite article 'a' modifies 'solution', not 'software', in this case in spite of preceding 'software' in this case.

PROBLEM: There is the verb quicken to make something quick or faster, but Merriam-Webster doesn't list slowen. What is the verb to make something slow (as in 'reduce in speed', not 'something that is slow')?.

SOLUTION:
The word slow itself can be used as a verb. It is an antonym for quicken Slow, from M-W verb to make (something, such as a car) move at a lower speed; to begin to move at a lower speed; to become slower 'the car slowed to a halt'