There are two problems with this. The first is that the two words 'a lot' are often written as 'alot', as if it were one word. You won't find this word in any dictionary, though. (You will find the word 'allot', which means 'give out' or 'distribute', but that's entirely different).

The second problem is that 'a lot of' is informal, bordering on slang, and almost always inappropriate in formal or academic writing. Instead, try using 'much', 'many' or 'most'.

This word has the general sense of 'coming out' or 'emerging from somewhere/someone', as in the phrase 'issue forth', like a river issuing into the sea. An 'issue' can be an edition of a newspaper or magazine; the resolution, result or final outcome of a problem or argument; or even the children of a marriage. It does not mean 'a problem' or 'an argument'.

'Problem' is still a good and well-known word: use it.

There has been a fashion in the last few years to use 'multiple' instead of the more obvious and clearer word 'many'. 'Multiple' has a specific and very definite meaning in mathematics or statistics, but outside there, it is usually used wrongly. 'Many' is usually much clearer.

Whenever you are thinking of writing either of these, instead write 'use' or 'help'. They are clearer, simpler and everyone will know what you mean.

It's a common mistake to use a figure instead of a word in sentences that use numbers. Thus you should not write, 'The event occurred 4 times over 3 hours'. This should read: 'The event occurred four times over three hours.' Only start using numerals/figures when you get to numbers above twenty. Thus, write eight or seventeen, but 29 or 73, for example. Even then, write the key decad-words like 'thirty', 'sixty', 'ninety', for example, as words, not numbers.

• Years.  Let's dispose of a common mistake first - when writing about decades (groups of ten years). You never need to write "the 1960's", or "the 80's" for example, putting an apostrophe between the number and the s. When you write "the 1960s ", or any decade, you are meaning the whole group of ten years that make up that decade, so the word is a plural. It therefore gets written like most other plurals, simply by adding an 's'. No apostrophe is needed (see below for more on why). So a correct sentence might read:
  The 1960s were the decade when the Beatles conquered the world with their new style of music.
• Showing Plurals. If a word is plural, meaning two or more of something, its plurality is shown by putting an 's' at the end of the word. There is never a need to put an apostrophe before the 's'. So you would write 'a group of authors' 'a dozen eggs', 'a herd of cows', 'the citizens of New Zealand' for example.
  • There are some words of Latin origin that end in '-sis' , such as thesis, crisis, emphasis. For these words, just change the '-sis' to a '-ses', and do nothing else: theses, crises, emphases, and so on.
  • Some other nouns, fortunately not many, have different plural forms altogether. These are some of the common ones you should watch for: radius/radii; criterion/criteria; woman/women; phenomenon/phenomena; child/children
• Apostrophes If you want to indicate possession or ownership of something, then you must use the apostrophe + s method. So, write 'the writer's opinion', 'the car's number-plate', 'the jury's verdict', 'the day's end' and so on.
  • What should you do if the 'possessor or owner' word already ends in an 's', as in words like Thomas, glass, or circus, for example? For words like these, the rule is slightly different. Add an apostrophe, but don't add an 's' to follow it. So, write 'Thomas' car', 'the glass' contents', 'the circus' owner'.

These two are often confused. 'Later' means 'at a time after something else happened', and it should only be used when the idea of time is a part of the meaning and usage. So you might say: 'I switched it on at exactly two o'clock - twenty minutes later, the alarm went off.'

'Latter' refers to the second of two things that have just been mentioned, usually in the immediately previous sentence or phrase. For example: 'When they were offered the choice of a day at the zoo or a visit to the skating rink, the students overwhelmingly chose the latter.' This means that almost all of the students wanted to go ice-skating.

There are some other common Spelling Confusions that regularly appear in people's writing. Check what each means and which one you want when you are writing.

• Loose (not tight) / lose (mislay)
• form / from
• too / two / to
• there / their / they're
• where (location) / were (time)
• lead (present tense) / led (past tense)
• your / you're

This can be a minefield of conflicting usages and rules. This is the best guide I can offer:

Use double quotation marks (" ") for extracts from another writer's work being copied into your own text, or if you are writing words spoken in a conversation, as novelists do.

Use single quote marks (' ') if you are isolating a word or phrase and wanting to draw attention to it because of its usage or special meaning, or if it is being used in a colloquial or metaphorical way.

[Note that if you are reading texts written in the USA, they reverse the above rule. Go figure, as they say there.]

You should know, too, that there seems to be a tendency among many writers today not to use double quote marks, and instead to use only single quotes in all situations. Perhaps this is because double quotes seem to be more intrusive and overly dominant in the look of the whole page of text. Another modern habit is to underline or to use italics instead of single quotes. This is all optional, though - choose whatever you prefer, or what your academic advisor suggests, and then just use it regularly.